.*>**' "-*-: A- A if* *- * '.>>■■ ' "*»^ /7V-; / t: ^< X r ' A ^ %y^ .;><"- >*HS ,r J ■m r ^> 4^r .v* ^ fee" DISCOVERY REPORTS VOLUME V Issued by the Discovery Committee Colonial Office, London on behalf of the Government of the Dependencies of the Falkland Islands VOL JME V CAMBRIDGE AT THE UNIVERSITY PRESS 1932 QII5 k.5 DISCOVERY REPORTS $**.<* I [Discovery Reports. Vol. V, pp. 1-326, Plate I, August, 1932.] AMPHIPODA By K. H. BARNARD, D.Sc, F.L.S. CONTENTS Introduction page 3 List of stations at which Amphipoda were collected, with the species obtained at each station . 6 General remarks and observations iq Systematic account 23 Appendix: Major Barrett-Hamilton's Collection 315 List of literature ^16 Index ~ 2I Plate I following page 326 CONTENTS AMPHIPODA (published 29th August, 1932) By K. H. Barnard, D.Sc, F.L.S. Introduction p a g e 3 List of Stations at which Amphipoda were Collected, with the Species obtained at each Station 6 General Remarks and Observations 19 Systematic Account 28 Appendix: Major Barrett- Hamilton's Collection 315 List of Literature 316 Index 321 Plate I ................ following page 326 THE VASCULAR NETWORKS (RETIA MIRABILIA) OF THE FIX WHALE {BALAENOPTERA PHY S ALUS) (published 6th September, 1932) By F. D. Ommanney, A.R.C.S., B.Sc. Introduction page 329 The Thoracic Rete 331 The Basicranial Rete 348 The Inguinal Plexus ~". 353 Discussion 356 Summary 361 List of Literature 362 THE URINO-GENITAL SYSTEM OF THE FIN WHALE {BALAENOPTERA PHY S ALUS) (published 26th September, 1932) By F. D. Ommanney, A.R.C.S., B.Sc. Introduction page 365 The Male Genital System 366 The Female Genital System 391 Nerves of the Genital Region 410 The Urinary System 412 Discussion 439 Summary 443 List of Literature 445 Appendix: Dimensions and Growth of the Kidney of Blue Whales (B. muscllus) and Fin Whales (5. physalus) 447 Plates II and III following page 466 V1 CONTENTS LOBSTER-KRILL: ANOMURAN CRUSTACEA THAT ARE THE FOOD OF WHALES (published 17th November, 1932) By L. Harrison Matthews, MA Material Examined ... , page 469 Distribution 4/0 Swarming 470 Characters separating Munida subrugosa and Af. crecaria and their post-larval Stages 471 Note on the History of the Species 473 Early Records of Shoals of the Grimothea Stage of Af. grec4ri4 4/9 Lobster-Krill the Food of Birds and Fishes o Lobster-Krill as Whale Food . . 402 Bibliography „ 484 PLATE IV following page 484 AMPHIPODA By K. H. Barnard, d.Sc, f.l.s. (Plate I and text-figs 1-174.) INTRODUCTION The collection of Amphipods made during the cruises of the R.S.S. 'Discovery' and the R.S.S. 'William Scoresby,' and by the staff of the Marine Biological Station at South Georgia during the years 1925-7, is a large one, comprising approxi- mately 6600 specimens, of which about 4550 are Gammaridea, 1650 Hyperiidea, and 400 Cyamidea. The Lysianassidae alone are represented by over 1100 specimens. Out of a total number of 179 genera and 326 species, 19 genera and 107 species were considered as new. Of these 17 genera and 18 species were described for the first time in a pre- liminary notice in Ann. Mag. Nat. Hist. (10), vn. pp. 425-30, 193 1. There are also 5 new varieties; and 1 new species described from a specimen in the South African Museum. It would be no exaggeration to describe this collection as the most important brought back by any expedition since the days of the U.S. Exploring Expedition and the ' Challenger.' It is probably the most comprehensive and richest collection from one particular geographical region, certainly as far as concerns the southern hemisphere. Besides the bulk of the collection, which was made in the area specially investigated, a considerable amount of important material was secured on the outward and home- ward voyages, and during the two winter cruises to South Africa. The size of the collection is due to the enthusiasm and energy of the staff. It is evident that no opportunity was lost of making the investigation as thorough as possible. The staff is to be congratulated not only on having obtained so much material, but also on having taken so much care in preserving it. Except for a small minority of specimens, which were unavoidably mutilated by the means of capture, the whole collection is in excellent condition. Moreover, in a large number of instances, colour notes on the living animals, colour sketches, photographs, and biological data were made. The labour thus entailed must have been enormous, when it is remembered that various kinds of animals come up in the dredge or trawl, each of which requires special methods of preservation. In addition to these words of praise for the staff in general for having amassed such a valuable collection, I have to express my thanks to Dr S. Kemp, the leader of the expedition, for having entrusted me with the examination of it. In accepting the under- taking I was fully aware of the disadvantages attending residence in the southern hemisphere, far from libraries and, even more necessary, the collections made by previous Antarctic expeditions. The importance of examining these type collections was not fully realized until the study of the Discovery collection was under way and : l «friculties of identification began to crop up. Win, -he advent of further and larger collections from the Antarctic the earlier 4 DISCOVERY REPORTS descriptions get subjected more and more to the fire of criticism. It is comparatively easy to sort out the specimens into species; the assignation of names, giving due credit to earlier authors, is the difficulty. All praise is due to those who have paved the way in the study of Antarctic and sub-Antarctic Amphipods. It is inevitable that pioneers should leave a few stones, sticks and snags as stumbling-blocks to those who follow. It takes much work to make a well-defined path, and also to arrive at a clear-cut definition of a "species." It is also inevitable, with an ever more searching analysis of specific characters, that even the most elaborate descriptions will often be found to lack just the precise informa- tion which a later student requires. Therefore, I realize only too well the deficiencies, and no doubt the errors, in the present report. In many instances I have been led to conclusions differing from those of other writers. In some cases I have utilized characters which have not been utilized before, with the result that perhaps it will at first have made confusion worse con- founded. This is not really so, but it means that many precious records are not available for the discussion of problems of geographical distribution until the material has been re-examined. The final settlement of such questions must be left to a student vhc Las the opportunity of making a critical study and comparison of the Antarctic material now preserved in the museums at London, Paris and Berlin. With reference to the times of day of the captures as set out in the Station List, I would like to remark on the convenience in having the hours between sunset and sun- rise printed in heavy type. This very greatly facilitates working out the daily bathy- metrical migration of certain species. I also wish to thank Dr W. T. Caiman, F.R.S., and Dr Isabella Gordon, of the British Museum, for their kindly help in giving me transcriptions, tracings, and answers to many queries. When entrusting me with the collection of Terra Nova Amphipods, Dr Caiman included also a small collection of specimens made in South Georgia by Major Barrett- Hamilton. The identifications of these have been included as an appendix to the present report with the concurrence of Dr Kemp. I have also seen some MS. notes on a few Amphipods from the Quest Expedition, by the late Dr Chilton. These do not extend our knowledge of the distribution of the species beyond what is recorded in the present report, with the exception of one species (see infra, p. 54), and they are therefore not included here. I have not seen the specimens. The important paper of Dr Schellenberg (March 193 1) on the Gammarids of the Swedish Antarctic Expedition and other collections was received after my MSS. had gone to press 1 . This explains why only the obvious and certain synonyms have been struck out. There are probably other synonyms among the species here described as new, but which are better reserved for more deliberate consideration than can be given in the present circumstances. 1 Forwarded on February 13 and received by the Discover}- Committee on March 10, 193 1. GEAR GEAR In the list of stations the following symbols represent the various kinds of gear used : B Oblique. H Horizontal. V Vertical. BTS Small beam trawl. Beam 8 ft. in length (2-45 m.): mesh at cod-end J in. (12-5 mm.). DC Conical dredge. Mouth 16 in. in diameter (40-5 cm.), with canvas bag. DL Large dredge. Light pattern, 4 ft. in length (1-2 m.). DLH Large dredge. Heavy pattern, 4 ft. in length (1-2 m.). DS Small dredge. 2 ft. in length (06 m.). LH Hand lines. N4-TI N7-TJ Nets with mesh of 4 mm. or 7 mm. (0-16 in. or 0-28 in.) attached to back of trawl. N 70 70 cm. tow-net. Mouth circular, 70 cm. in diameter (27-5 in.): mesh graded, at cod-end 74 to the linear inch. N 100 1 m. tow-net. Mouth circular, 1 m. in diameter (3-3 ft.): mesh graded, at cod-end 16 to the linear inch. From July 1, 1927, this net was replaced by another, of similar pattern, but with the cod-end made of stramin with 11-12 meshes to the linear inch. N 200 2 m. tow-net. Mouth circular, 2 m. in diameter (6-6 ft.): mesh graded, at cod-end 4 mm. (o-i6in.). N 45° 4-J- m. tow-net. Mouth circular, \\ m. in diameter (14-8 ft.): mesh graded, at cod-end 7 mm. (o-2S in.). NC 50 Coarse 50 cm tow-net. Mouth circular, 50 cm in diameter (19-5 in.): 25 meshes to the linear inch. NCS-D) NCS-T f Tow-net °f coarse silk, with 16 meshes to the linear inch, attached to trawl or other net. NH . Hand net. NHS High speed tow-net. Mouth 3 in. in diameter (7-5 cm.): mesh 74 to the linear inch. NRL Large rectangular net. Frame 8 ft. long and z\ ft. wide (2-45 m. ;< 07 m.) with bag of \ in. mesh (12-5 mm.). NRM Medium rectangular net. Frame 4 ft. long and i\ ft. wide (1-2 m. x 0-38 m.) with bag of 7 mm. mesh (o-2S in.). OTC Commercial otter trawl. Head rope 80 ft. long (24-5 m.) : mesh at cod-end r \ in. (3-8 cm.). OTL Large otter trawl. Head rope 40 ft. long (12-2 m.): mesh at cod-end \\ in. (3-2 cm.). KM Mussel rake. TNL Large fish-trap. Rectangular, 4 ft. by 4 ft. by z\ ft. (1-2 m. x 1-2 m. x 075 m.), with netting or wire of \ in. mesh (12-5 mm.). TYF Young fish trawl. Mouth about 20 ft. in circumference (6 m.) : bag of stramin with 1 1-12 meshes to linear inch. Fished until July 1926 with poles and otter-boards, thereafter attached to a circular tow-net frame 2 m. in diameter (6-6 ft.). IO. x. 25 II. x. 25 14. claiisi x. 25 , Bov 14. x. 25 DISCOVERY REPORTS LIST OF STATIONS AT WHICH AMPHIPODA WERE COLLECTED, WITH THE SPECIES OBTAINED AT EACH STATION R.R.S. 'DISCOVERY' 41 37' N, 12 30' W. N 200. 0-9000 m. : Cystisoma peUucidum (W. Suhm). 39° 05' X, 13 04' W. N 100. o m. : Phronima atlantica, Guer. 34°23'X, 14 32' W. N 70. o m., day: Corophium bonellii (M. Edw.); Oxycephalic Caprella equilibra, Say. 33° 37' ^> x 4° 39' W. " I0 °- ° m - : Oxycephalic clausi, Bov. 16. x. 25. 29 26' N, 15 07' W. N 200. 0-900 m. : Scina crassicornis (Fabr.) ; Phronima sedentaria (Forsk.); PJiabdosoma zchitei, Bate. From stomach of Naucrates ductor: Platyscelus ovoides (Claus). 25. x. 25. 17 24' N, 18 15' W. From stomach of Thymus pelamys : Phronima sedentaria (Forsk.). 28. x. 25. i3°25'N, i8°22'W. N450. 0-9000 m. : Scina curvidactyla, Chevr. ; Cystisoma peUucidum (W. Suhm) ; C. fabricii, Stebb. ; Phronima sedentaria (Forsk.). 2. xi. 25. 6° 55' N, 15 54' W. N 200. 0-800 m. : Scina vosseleri, Tan. ; Vibilia cultripes, Voss. ; Cystisoma peUucidum (\Y. Suhm); C. fabric.':, frt.bb. 12. xi. 25. 2° 20' S, I2°45'W. N 100. om. : Vibilia -ciatrix, Bov.; Paraphronima gracilis, Claus ; P. crassipes, Claus ; Phronima sedentaria (Forsk.) ; P. atlantica, Guer. ; Phronimella elongata (Claus) ; Phrosina semilunata, Risso ; Thyropus sphaeroma, Claus. 13. xi. 25. 3 50' S, 12 54' W. N 200. o m. : Phronima sedentaria (Forsk.) ; P'. curvipes, Voss. 29. xi. 25. 25 47' S, 14 48' W. NH. o m. : Brachyscelus rapax, Claus. St. 1. 16. xi. 25. Clarence Bay, Ascension Island. NRM. 16-27 m., cr ^- s > sn - : Maera ascensionis, n.sp. ; Ampithoe ? brasiliensis (Dana). St. 2. 17. xi. 25. Clarence Bay, Ascension Island. Shore collecting (and from buoy, sic on label) : Leucothoe spinicarpa (Abildg.); Hyale sp. ; Ampithoe ? brasiliensis (Dana). St. 3. 3. xii. 25. 29 31' S, 13 56' W. N 200. 500-700 m., day: Phronima sedentaria (Forsk.). St. 4. 30. i. 26. Tristan da Cunha. DL. 40-46 m. : Ampithoe brevipes (Dana); Jassa pusilla (Sars) ; Parajassa tristanensis (Stebb.) ; Caprella acutifrons, Latr. ; Pseudaeginella tristamiLi's (Stebb.). From stomach of Perca antarctica, Blue Fish (see note, p. 27): Vibilia armata, Bov.; Cyllopus magellanicus, Dana; Phronima sedentaria (Forsk.). N 100. 0-10 m., day: Phronima sedentaria (Forsk.). St. 5. 31. i. 26. Quest Bay, Tristan da Cunha. NRM. 7-12 m., g. r.: Stenothoe sp.; Pontogeneia tristanensis, n.sp.; Ischyrocerus anguipes, Kroy., var. longimanus, Hasw. Shore collecting and from stream through settlement : Orchestia platensis, Kroy. St. 6. 1. ii. 26. Tristan da Cunha, 3 miles N 30 E of settlement. DL. So-140 m., r. : Paramoera tristanensis, n.sp. St. 8. S. ii. 26. 42°36'S, 18 19' W. N 200. 600-700 m., day-night: Cyphocaris richardi, Chevr.; Parandania boecki (Stebb.). N 100 H. 0-10 m., day: Parathemisto gaudichaudii (Guer.). St. 9. 11. ii. 26. 46' 1 1' S, 22 27' W. N 200. 1250 (-0) m., day: Parandania boecki (Stebb.); Parathemisto gaudichaudii (Guer.). N100H. 0-5 m., day: Primnomacropa, Guer. N450. 350o(-o)m., day : Lanceola serrata, Bov. St. 24. 14. iii. 26. 10 miles N 72 E of Jason Light, South Georgia. N 100 H. 60 (-0) m., day: Parathemisto gaudichaudii (Guer.). St. 25. 14. iii. 26. 18 miles N 6o°E of Jason Light, South Georgia. N 100 H. 0-5 m., night: Cyllopus lucasii, Bate. STATION-LIST 7 St. 26. 14. iii. 26. 26-5 miles N 54 E of Jason Light, South Georgia. N 100 H. 60 (-0) m., night: Cyllopus lucasii, Bate; Parathemisto gaudichaudii (Guer.). St. 27. 15. iii. 26. West Cumberland Bay, South Georgia. DL. nom.,m.T.:Ampeliscabouvieri, Chevr. \Haplodps securiger, Brnrd. ; Heterophoxtis videns, Brnrd. ; Giiathiphimcdia mandibularis, Brnrd. ; Liljeborgia longicornis, Schell. ; Methalimcdon nordenskjoldi, Schell. ; Epimeria excisipes, n.sp. ; Eusirus antarcticus, Thorns. ; Schraderia gracilis, Pfr. St. 30. 16. iii. 26. West Cumberland Bay, South Georgia. DLH. 251m., m. st. : Aeginoides gaussi, Schell. St. 32. 17. iii. 26. 22-S miles N 70!° E of Jason Light, South Georgia. N 100 H. 50 (-0) m., night : Cyllopus magellanicus, Dana ; C. lucasii, Bate. St. 33. 18. iii. 26. 33 miles N 37 E of Jason Light, South Georgia. N 100 H. 50 (-0) m., day: Parathemisto gaudichaudii (Guer.). N 100 H. 90 (-0) m., day: Primno macropa, Guer. St. 35. 18. iii. 26. 53 miles N 40° E of Jason Light, South Georgia. N 100 H. 90 (-0) m., day: Cyllopus tnagellanicus, Dana; Primno macropa, Guer. N 100 H. 50 (-0) m., day: Parathemisto gaudichaudii (Guer.). St. 36. 18. iii. 26. 38 miles N 39 E of Jason Light, South Georgia. N 100 H. 50 (-0) m., night: Vibilia antarctica, Stebb. 90 (-0) m., night: Vibilia antarctica, Stebb. ; Cyllopus lucasii, Bate ; Hyperia spinigera, Bov. ; Parathemisto gaudichaudii (Guer.). 0-5 m., night: Cyllopus magellanicus, Dana; C. lucasii, Bate; Parathemisto gaudichaudii (Guer.). St. 37. 18-19. '"• 26. 28 miles N 36 E of Jason Light, South Georgia. N 100 H. 50 (-0) m., night : Cyllopus magellanicus, Dana ; C. lucasii, Bate. St. 38. 19. iii/26. 18-5 miles N 33 E of Jason Light, South Georgia. N 100 H. 0-5 m., night: Cyllopus lucasii, Bate. 90 (-0) m., night: Primno macropa, Guer. St. 39. 25. iii. 26. East Cumberland Bay, South Georgia. OTL. 179-235 m., gy.m.iAcidostomella cultrifera, Schell. ; Orchomenella rossi (Wlkr.) ; O. macronyx, Chevr. ; Pachychelium davidis, Steph. ; Andaniotes linearis, n.sp.; Parharpinia rotundifrons, n.sp.; Leucothoe spinicarpa (Abildg.); Seba antarctica, Wlkr. ; Metopella ovata (Stebb.) ; Colomastixfissilingua, Schell. ; Acanthonotozomella oatesi, Brnrd.; Epimeria intermedia, Schell.; Polycheria antarctica (Stebb.); Eurystheus purpurescens, n.sp.; Caprellinoides mayeri (Pfr.); Dodecas reducta, n.sp.; Aeginoides gaussi, Schell. St. 41. 28. iii. 26. i6| miles N 39 E of Barff Point, South Georgia. N 70. 240-150 m., day: Pseudorchomene coatsi (Chilton); Halice profundi, n.sp. ; Parathemisto gaudichaudii (Guer.). 100- 50 m., day: Parathemisto gauaichaudii (Guer.). St. 42. i.iv. 26. Off mouth of Cumberland Bay, South Georgia. N 7-T and OTL. 120-204 m., m. : Aristias antarcticus, Wlkr. ; Lepidepecrcella ovalis, n.sp. ; Orchomenella rossi (Wlkr.) ; O. macronyx, Chevr.; Pseudorchomene coatsi (Chilton); Andaniotes linearis, n.sp.; Ampelisca eschrichtii Kroy. ; A. macrocephala, Lilj.; Haploops securiger, Brnrd.; Leucothoe spinicarpa (Abildg.); Proboloides typica (Wlkr.) ; P. carinata, Schell. ; P. crenatipalmatus (Stebb.) ; Iphimediella margueritei, Chevr. ; Gnathiphi- mediamacrops, n.sp. ;Pagetinagenarum, Brnrd. ;Oedicei'oides?nacrodactylus, Schell. ;Ephneriaexcisipes, n.sp. ; Parepimeria crenulata, Chevr. ; Melphidippa antarctica, Schell. ; Eurystheus distichon, Brnrd. ; Podocerus sp. ; Caprellinoides mayeri (Pfr.) ; Dodecasella elegans, Brnrd. ; Aeginoides gaussi, Schell. St. 44. 3. iv. 26. 32 miles N 51 E of Jason Light, South Georgia. N 100 H. 0-5 m., night: Cyllopus lucasii, Bate. St. 45. 6. iv. 26. 2-7 miles S 85 E of Jason Light, South Georgia. N 4-T and NCS-T. 238-270 m., gy.m. : Aristias antarcticus, Wlkr.; Tryphosa kergueleni (Miers); Lepidepecreella avalis, n.sp.; Orchomenella rossi (Wlkr.) ; O. macronyx, Chevr. ; Pseudorchomene coatsi (Chilton) ; Pagetina genarum, Brnrd.; Halice profundi, n.sp.; Oediceroides calmani, Wlkr.; O. macrodactylus, Schell.; Syrrhoe psychrophila, Monod; Epimei-ia puncticulata, Brnrd.; Melphidippa antarctica, Schell.; Paraceradocus miersii(Ph.); Eurystheus dimorphus, n.sp.; E. distichon, Brnrd.; Dodecasella elegans, Brnrd. 8 DISCOVERY REPORTS St. 46. 21. iv. 26. 51 13' S, 49 50' W. N 100 H. 0-5 m., night: Vibilia antarctica, Stebb. St. 47. 23. iv. 26. 50°55'S, 54°38'W. N 100 H. 0-5 m., night: Vibilia antarctica, Stebb.; Cyllopus rnagellanicus, Dana ; Parathemisto gandichaudii (Guer.). St. 49. 3. v. 26. 13-5 miles N5i°E of Cape Bougainville, East Falkland Island. N100H. 0-5 m., night: Vibilia antarctica, Stebb.; Parathemisto gandichaudii (Guer.). St. 51. 4. v. 26. Off Eddystone Rock, East Falkland Island. DLH, OTL, and N 4-T. 105-115 m., i.s.:A?naryllis macrophthalma, Hasw. ; Tryphosites chevreuxi, Stebb. ; Orchomenellacavimanus (Stebb.) ; Urothoe falcata, Schell. ; Leucothoe spinicarpa (Abildg.) ; Seba saundersii, Stebb. ; Proboloides porcel- lanus, n.sp. ; Colomastix castellata, n.sp.; Labriphimedia vespuccii, Bmrd.; Liljeborgia longicornis, Schell.; Monoculodes vallentini (Stebb.); Chosroes incisus, Stebb.; PJiachotropis antarctica, n.sp.; Atyloella dentata, n.sp. ; Polycheria antarctica (Stebb.) ; Eurystheus remipes, n.sp. ; Podocerus ? brasi- liensis (Dana) ; Parathemisto gaudichaudii (Guer.). St. 53. 12. v. 26. Port Stanley, East Falkland Island. Hulk of 'Great Britain.' 0-2 m., kelp roots: Pariphimedia normani (Cunn.); Panoploea macrocystidis, n.sp.; Halirages huxleyanns (Bate); Haplocheira robnsta, n.sp.; Ampithoe brevipes (Dana). St. 54. 15. v. 26. Port Stanley, East Falkland Island. Shore collecting: Paramoera obliquimanus, n.sp.; Haplocheira robiista, n.sp.; Corophium cylindricnm (Say). St. 55. 16. v. 26. Entrance to Port Stanley, East Falkland Island. BTS. 10-16 m.; Acontiostoma marionis, Stebb.; Halirages huxleyanus (Bate); Eurystheus eurypodii, n.sp.; Ampithoe brevipes (Dana). St. 56. 16. v. 26. Sparrow Cove, Port William, East Falkland Island. BTS. iol— 16 m. : Halirages huxleyanus (Bate); H. regis (Stebb.); Pontogeneia simplex (Dana); Atyloella magellanica (Stebb.); Ampithoe brevipes (Dana). St. 57. 16. v. 26. Port William, East Falkland Island. BTS and NCS-T. 15 m.: Liljeborgia kinahani (Bate) var. falklandica n. St. 58. 19. v. 26. Port Stanley, Falkland Islands. RM. 1-2 m., piles of jetty: Pachychelium davidis, Steph. ; Atyloella magellanica (Stebb.); Haplocheira robusta, n.sp. St. 62. 22. v. 26. 49° 22' S, 54 48' W. N 100 H. 45 (-0) m., night: Vibilia antarctica, Stebb. N 100 H. 90 (-0) m., night: Phronima sedentaria (Forsk.). St. 64. 22. v. 26. 48 34' S, 53 34' W. N 100 H. 0-5 m., night: Platyscelus o-voides (Claus). St. 66. 23. v. 26. 48 09' S, 52 50' W. N 100 H. 0-5 m., night: Cyllopus rnagellanicus Dana. W 100 H. 45 (-0) m., night: Hemityphis rapax (M. Edw.). St. 67. 23. v. 26. 47°i8'S, 5i°52'W. N 70 H. 45 (-0) m., day: Vibilia australis, Stebb.; Cyllopus rnagellanicus, Dana. St. 69. 25. v. 26. 45 06' S, 49 00' W. N 100 H. 90 (-0) m., night: Vibilia viatrix, Bov. ; Para- phronima crassipes, Claus. St. 71. 30. v. 26. 43 20' S, 46 02' W. TYF. 2000 (-0) m., day: Cyphocaris richardi, Chevr.; Parandania boecki (Stebb.); Eusiroides stenopleura, n.sp.; Micromimonectes irene, Wolt.; Lanceola serrata, Bov. ; Scina curvidactyla, Chevr. ; Vibilia antarctica, Stebb. ; V. armata, Bov. ; V.pyripes, Bov. ; Cyllopus rnagellanicus, Dana; Cystisomafabricii, Stebb. ; Parathemisto gaudichaudii (Guer.); Phronima sedentaria (Forsk.) ; Primno macropa, Guer. St. 72. 1. vi. 26. 41 43' S, 42° 20' W. N 450. 2000 (-0) m., night: Cyphocaris richardi, Chevr.; Parandania boecki (Stebb.); Lanceola remipes, n.sp.; Parathemisto gaudichaudii (Guer.); Phronima sedentaria (Forsk.). St. 76. 5. vi. 26. 39° 50' S, 36 23' W. N 450. 1500 (-0) m., day: Cyphocaris richardi, Chevr.; Parandania boecki (Stebb.) ; Lanceola pacifica, Stebb. ; Scina curvidactyla, Chevr. ; Vibilia viatrix, Bov. ; Phronima sedentaria (Forsk.). STATION-LIST 9 St. 78. 12. vi. 26. 35 iS' S, i9°oi'W. TYF. 1000 (-0) m., day: Cyphocaris richardi, Chevr. ; C. anonyx, Boeck; C. challengeri, Stcbb. ; Metacyphocaris lielgae, Tatt. ; Katius obesiis, Chcvr. ; Parandania boecki (Stebb.); Lanccola serrata, Bov. ; Scina airvidactyla, Chevr.; S. incerta, Chevr.; S. borealis (Sars) ; Vibilia armata, Bov. ; Paraphronima crassipes, Claus ; Cystisoma pellucidum (W. Suhm) ; Parathemisto gaudichaudii (Guer.) ; Primno macropa, Guer. St. 80. 17. vi. 26. 2,-' 46' S, io° 00' W. N 200 H. 30-0 m., night: Scina crassicornis (Fabr.). St. 81. 18. vi. 26. 32° 45' S, 8° 47' W. N450H. 650 (-o)m., day: Cyphocaris richardi, Chevr.; C. anonyx, Boeck; C. faurei, Brnrd.; Lanceola pacifica, Stebb.; Scina crassicornis (Fabr.); S. sub- marginata, Tatt.; Vibilia armata, Bov.; V. cultripes, Voss.; Cyllopus magellanicus, Dana; Cystisoma fabricii, Stebb.; Phronima sedentaria (Forsk.); P. curvipes, Voss.; Parascelus typhoides, Claus. St. 83. 21. vi. 26. 32" 30' S, i°23'W. N 200 H. 650 (-0) m., night: Cyphocaris challengeri, Stebb. ; C. faurei, Brnrd. ; Scina crassicornis (Fabr.) ; Brachyscclus crusculum, Bate ; Platyscelus ovoides (Claus). St. 84. 22. vi. 26. 32 ; 52' S, i° 55' E. NCS-D. 2000-0 m., night: Cyphocaris richardi, Chevr.; Vibilia viatrix, Bov. ; Paraphronima gracilis, Claus ; Hyperioides lofigipes, Chevr. St. 85. 23. vi. 26. 33 3 07'S, 4 30' E. N450H. 2000 (-0) m., night: Metacyphocaris helgae, Tatt.; Parandania boeck: (Stebb.); Enandania gigantea (Stebb.); Scypholanceola vanhoeffeni, Wolt. ; Scina curvidactyla, Chevr. ; Pegohyperia princeps, Brnrd. ; Phronima sedentaria (Forsk.). N 70 V. 500-0 m., day: Platyscelus ovoides (Claus). St. 86. 24. vi. 26. 33 ; 25' S, 6° 31' E. N 450 H. 1000 (-0) m., day: Cyphocaris richardi, Chevr.; C. faurei, Brnrd. ; Lanceola serrata, Bov. ; L. pacifica, Stebb. ; Scypholanceola vanhoeffeni, Wolt. ; Scina crassicornis (Fabr.) ; Phronima sedentaria (Forsk.) ; Streetsia challengeri, Stebb. St. 87. 25. vi. 26. 33 : 53' S, 9° 26' E. TYF. 1000 (-0) m., day: Cyphocaris anonyx, Boeck; C. challengeri, Stebb. ; Andaniexis australis, n.sp. ; Stenopleura atlantica, Stebb. ; Eusirella elegans, Chevr. ; Scypho'latueola vanhoeffeni, Wolt. ; Parascina fowleri, Stebb. ; Scina crassicornis (Fabr.) ; S. incerta, Chevr.; S. borealis (Sars); S. uncipes, Stebb. f. spinosa, Voss.; S. tullbergi (Bov.); Vibilia viatrix, Bov. ; V. propinqua, Stebb. ; V. armata, Bov. ; Paraphronima crassipes, Claus ; Hyperioides longipes, Chevr.; Phronima atlantica, Guer.; P. pacifica, Streets; Parapronoe campbelli, Stebb.; Streetsia challengeri, Stebb. ; Hemityphis rapax (M. Edw.). St. 88. 27. vi. 26. 34- 04' S, 13° 00' E. N 100 H. 3000-0 m., day : Vibilia armata, Bov. ; Hyperi- oides longipes, Chevr. ; Phronima sedentaria (Forsk.). St. 89. 28. vi. 26. 34 : 05' S, 16 00' E. TYF. 1000 (-0) m., day: Cyphocaris richardi, Chevr. ; C. anonyx, Boeck; C. challengeri, Stebb.; Andaniexis australis, n.sp.; Synopioides macronyx, Stebb.; Stenopleura atlantica, Stebb. ; Lanceola serrata, Bov. ; Scypholanceola vanhoeffeni, Wolt. ; Scina crassi- cornis (Fabr.); S. iiurerta, Chevr.; S. langhansi, Wagl.; S. borealis (Sars); S. uncipes, Stebb. f. affinis, Wagl. ; S. oedicarpus, Stebb. ; Vibilia propinqua, Stebb. ; V. armata, Bov. ; Cyllopus magellanicus, Dana ; Paraphronima crassipes, Claus; Hyperioides longipes, Chevr.; Dairella latissima, Bov.; Phronima atlantica, Guer. ; Phrosina semilunata, Risso ; Primno macropa, Guer. ; Euprono'e minuta, Claus ; Lycaca nasuta, Claus ; Brachyscelus crusculum, Bate ; Platyscelus ovoides (Claus) ; Hemityphis rapax (M. Edw.). St. 90. 10. vii. 26. Simon's Town, False Bay, South Africa. NRM. 10-12 m.: Lysianassa zariegata (Stmpsn) ; Ampelisca palmata, Brnrd. ; Liljeborgia kinahani (Bate) var. capensis n. ; Melita inaequistylis (Dana). St. 91. 8. ix. 26. Off Roman Rock, False Bay, South Africa. NRL. 35 m.,s.: Amaryllis macroph- thalma, Hasw.; Lysianassa variegata (Stmpsn); Tryphosa onconotus, Stebb.; Ampelisca brevicomis, Costa; Phylluropus capensis, n.sp. ; Aora typica, Kroy., var. gibbula n. ; Lemboides afer, Stebb. ; Photis '•"■iiiata, n.sp.; Eurystheus palmoides, n.sp. io DISCOVERY REPORTS St. 101. 14. x. 26. 33°5o'-34° 13'S, i6°04'-i5°49'E. N 450. 850-950 m., day: Cyphocaris richardi, Chevr. ; Katius obesus, Chevr. ; Lanceola pacifica, Stebb. ; Phronima sedentaria (Forsk.). N 450. 13 10-14 10 m., day : Cyphocaris richardi, Chevr. ; Parandania boecki (Stebb.) ; Lanceola serrata, Bov. ; Parathemisto gaudichandii (Guer.); Phronima sedentaria (Forsk.). 15. x. 26. N 450 H. 350- 400 (-0) m., night : Phronima sedentaria (Forsk.) ; Phrosina semilunata, Risso ; Anchylomera blossevillci, M. Edw. ; Brachyscelus criisadum, Bate; Oxycephalic clansi, Bov. St. 103. 30. x. 26. 39 04' S, 17 38' E. N70V. 500-250 m., day : Paraphronima crassipes, Claus. St. 105. 3. xi. 26. 44 32' S, 18 17' E. N100H. 117 m., day: Primno macropa, Guer. St. 107. 4. xi. 26. 45 03' S, 17 03' E. N450. 850-950111., day: Cyphocaris richardi, Chevr.; C. faurei, Brnrd. ; Katius obesus, Chevr. ; Parandania boecki (Stebb.) ; Lanceola serrata, Bov. St. 114. 12. xi. 26. 52 25' S, 9° 50' E. N450. 1310-1410111., day: Cyphocaris richardi, Chevr.; Parandania boecki (Stebb.); Eusiroides stenopleura, n.sp.; Lanceola serrata, Bov. St. 116. 14. xi. 26. 50 30' S, 5 34' E. N 100 H. 55 m., night: Eusirus microps, Wlkr.; Vibilia antarctica, Stebb. ; Cyllopus magellanicus, Dana ; Hyperiella dilatata, Stebb. ; Parathemisto gaudichaudii (Guer.). St. 120. 22. xi. 26. 51° 44' S, 5 19' W. N 100 H. 575-675 m., day: Sana borealis (Sars); Vibilia antarctica, Stebb. ; Parathemisto gaudichaudii (Guer.) ; Primno macropa, Guer. St. 122. 14. xii 26. Maiviken, West Cumberland Bay, South Georgia. Shore collectLig : Talorchestia scutigerula (Dana). St. 123. 15. xii. 26. Off mouth of Cumberland Bay, South Georgia. N 4-T and OTL. 230- 250 m., gy.m. : Shackletonia robusta, Brnrd. ; Tryphosa kergueleni (Miers) ; Orchomenella rossi (Wlkr.) ; O. macronyx, Chevr.; Ampelisca macrocephala, Lilj.; Haploops securiger, Brnrd.; Proboloides typica (Wlkr.); P. carinata, Schell. ; P. crenatipalmatus (Stebb.); Gnathiphimedia mandibulars, Brnrd.; G. sexdentata (Schell.) ; Oediceroides macrodactylus, Schell. ; Oradarea tridentata, n.sp. ; Auslropleiistes simplex, n.sp.; Epimeria excisipes, n.sp.; E. puncticulata, Brnrd.; Parepimeria crenulata, Chevr.; Eclysis similis, n.g., n.sp.; Melphidippa antarctica, Schell.; Eusirus antarcticus, Thorns.; Maera pfefferi, n.sp.; Paraceradocus miersii (Pfr.); Eurystheus dimorphus, n.sp.; E. distichon, Brnrd.; E. serricrus, n.sp.; Megamphopus blaisus, n.sp.; Dodecasella elegans, Brnrd.; Aeginoides gaussi, Schell. St. 125. 18-19. xii. 26. 53° 28' S, 36 20' W. N 100 H. 0-5 m., night: Vibilia antarctica, Stebb.; Hyperoche medusarum (Kroy.) ; Parathemisto gaudichaudii (Guer.). St. 128. 19. xii. 26. 53° 38' S, 37 08' W. N 100 H. 50 (-0) m., day: Parathemisto gaudichaudii (Guer.). St. 129. 19. xii. 26. 53 28' S, 37 08' W. N 100 H. 84 (-0) m., night: Vibilia antarctica, Stebb. ; N 100 H. 0-5 m., night: Vibilia antarctica, Stebb. St. 130. 20. xii. 26. 54 06' S, 36° 23' W. N 100 H. 38 m., day: Hyperoche medusarum (Kroy.). St. 132. 20. xii. 26. 53° 52' S, 35°58'W. N 100 H. 38 m., day: Parathemisto gaudichaudii (Guer.). St. 133. 20-21. xii. 26. 53 45' S, 35 46' W. N 100 H. 0-5 m., night: Vibilia antarctica, Stebb. N 100 H. 100 m., night: Vibilia antarctica, Stebb. St. 136. 21. xii. 26. 54 22' S, 35 21' W. N 100 H. 0-5 m., night: Parharpinia obliqua, n.sp.; Vibilia antarctica, Stebb. ; Parathemisto gaudichaudii (Guer.). N 100 H. 99 (-0) m., night: Vibilia antarctica, Stebb. St. 137. 22. xii. 26. 54°i9'S, 35°03'W. N 100 H. 66 m., day: Vibilia antarctica, Stebb.; Parathemisto gaudichaudii (Guer.). St. 138. 22. xii. 26. 54 17' S, 34 47' W. N 100 H. 77 m., day: Vibilia antarctica, Stebb. STATION-LIST n St. 140. 23. xii. 26. Stromness Harbour to Larscn Point, South Georgia. N 4-T. 122-136111., gn.m. st.: Uristcs gigas, Dana; Tryphosa kcrgueleni (Miers); T. triangularis, n.sp.; Lepidepecreella ovalis, n.sp.; Ampelisca bouvieri, Chevr.; Haplodps securiger, Brnrd.; Scba anlarctica, Wlkr.; Pro- boloides crenatipabnatus (Stebb.); Gnathiphimcdia mandibularis, Brnrd.; Echiniphimedia hodgsoni (Wlkr.); E. echinata (Wlkr.); Monoculodes scabriculosus, n.sp.; Methalimedon nordenskjoldi, Schell.; Syrrhoe psychrophila, ~S Ionod ; Epimeria excisipes, n.sp. ; E. puncticulata, Brnrd. ; E. intermedia, Schell. ; Parepimeriacrenulata, Chevr.; Melphidippa antarctica, Schell. ; Eusirus antarctiats,Thoms. ; Eurystheus dimorphus, n.sp.; E. serricrus, n.sp.; Megatnphopus b/aisus, n.sp.; Haplocheira barbimanus (Thorns.); Dodecasella elegans, Brnrd. St. 141. 29. xii. 26. East Cumberland Bay, South Georgia. BTS. 17-2710., m.: Tryphosa triangularis, n.sp.; Orchomenella acanthurus (Schell.); Parharpinia rotundifrons, n.sp.; Oradarea trident ata, n.sp.; Eusiroides georgianus, n.sp.; Djerboa furcipes, Chevr.; Schroder ia gracilis, Pfr. ; Paradexamine fissicauda, Chevr.; Megatnphopus blaisus, n.sp.; Haplocheira barbimanus (Thorns.). St. 142. 30. xii. 26. East Cumberland Bay, South Georgia. NCS-T and OTL. 88-273 m., m.: Allogaussia lobata, n.sp.; Orchomenella rossi (Wlkr.); Pseudorchomene coatsi (Chilton); Seba anl- arctica, Wlkr.; Halice profundi, n.sp.; Oradarea tridentata, n.sp.; Epimeria intermedia, Schell.; Polycheria anlarctica (Stebb.) ; Didymochelia spongicola, Brnrd. St. 144. 5. i. 27. Off mouth of Stromness Harbour, South Georgia. N 4-T and NCS-T. 155- 178 m., gn.m. s. : Uristes gigas, Dana ; Tryphosa ketgueleni (Miers) ; T. triangularis, n.sp. ; T. a.ialogica, n.sp. ; Andaniotes linearis, n.sp. ; Ampelisca eschrichtii, Kroy. ; Haplodps securiger, Brnrd. ; Proboloides typica (Wlkr.); P. crenatipalmatus (Stebb.); Acanthonotozomella oatesi, Brnrd.; Gnathiphimedia mandibularis, Brnrd. ; Liljeborgia longicomis, Schell. ; Paraperioculodes brevimanus, Brnrd. ; Oediceroides macrodactylus, Schell. ; Syrrhoe psychrophila, Monod; Oradarea tricarinata, n.sp. ; Epimeria excisipes, n.sp. ; Parepimeria crenulata, Chevr. ; Melphidippa antarctica, Schell. ; Eusirus antarcticus, Thorns. ; Rhachotropis antarctica, n.sp.; Schraderia gracilis, Pfr.; Maera pfefferi, n.sp.; Polycheria antarctica (Stebb.); Eurystheus dimorphus, n.sp. ; E. distichon, Brnrd. ; Megatnphopus blaisus, n.sp. ; Haplocheira barbimanus (Thorns.) ; Dodecasella elegans, Brnrd. St. 145. 7. i. 27. Stromness Harbour, South Georgia. BTS. 26-35 m -> w eedy ground: Cheiri- medon femoratus (Pfr.) ; Tryphosa triangularis, n.sp. ; Orchomenella acanthurus (Schell.) ; Gnathi- phimedia tnandibularis, Brnrd. ; Liljeborgia kinahani (Bate) var. georgiensis n. ; Oediceroides calmani, Wlkr.; Oradarea tridentata, n.sp.; Djerboa furcipes, Chevr.; Schraderia gracilis, Pfr. St. 146. 8. i. 27. 53 48' S, 35 37' W. DLH. 728 m., r. : Haplodps securiger, Brnrd. St. 148. 9. i. 27. Off Cape Saunders, South Georgia. N 4-T. 132-14S m., gy.m. st. : Andaniotes linearis, n.sp. ; Gnathiphimedia mandibularis, Brnrd. ; G. sexdentata (Schell.) ; Echiniphimedia hodgsoni (Wlkr.); E. echinata (Wlkr.); Oediceroides macrodactylus, Schell.; Epimeria excisipes, n.sp.; E. puncticulata, Brnrd. ; Melphidippa antarctica, Schell. ; Eurystheus dimorphus, n.sp. St. 149. 10. i. 27. Mouth of East Cumberland Bay, South Georgia. N 4-T and OTL. 200-23410., m. : Aristias antarcticus, Wlkr. ; Orchomenella rossi (Wlkr.) ; O. macronyx, Chevr. ; Andaniotes linearis, n.sp.; Leucothoe spinicarpa (Abildg.); Gnathiphimedia sexdentata (Schell.); Echiniphimedia hodgsoni (Wlkr.); E. echinata (Wlkr.); Oediceroides macrodactylus, Schell.; Oradarea tridentata, n.sp.; Melphidippa antarctica, Schell. ; Eusirus antarcticus, Thorns. ; Eurystheus dimorphus, n.sp. St. 151. 16. i. 27. 53 25' S, 35 15' W. N 450. 1025-1275 m., day: Parandania boecki (Stebb.). N 100 H. 500-625 m., day: Vibilia antarctica, Stebb. ; Parathemisto gaudichaudii (Guer.); Pritnno macropa, Guer. St. 152. 17. i. 27. 53°5i'S, 36°i8'W. DLH. 245 m., r.: Orchomenella cavimanus (Stebb.); Proboloides typica (Wlkr.); P. crenatipalmatus (Stebb.); Parepimeria crenulata, Chevr.; Melphidippa antarctica, Schell.; Maera pfefferi, n.sp.; Aeginoides gaussi, Schell. , 2 DISCOVERY REPORTS St. 153. 17. i. 27. 54 08' S, 36 27' W. DLH. 106 m., r. : Ampelisca bouvieri, Chevr.; Ilaploops securiger, Brnrd. St. 154. 18. i. 27. Jason Harbour to Larsen Point, South Georgia. N 4-T. 60-1 00 ni., .... • Orchomenella rossi (Wlkr.) ; Pseudorchomene coatsi (Chilton) ; Paraperioculodes brevimanus, Brnrd. ; Eur stheus dimorphus, n.sp. St. 156. 20. i. 27. 53°5i'S, 36°2i' W. DLH. 200-236 m., r. : Iris tes gigas, Dana; Tryphosa analogica, n.sp. ; Andaniotes linearis, n.sp. ; Iletcrophoxus videns, Brnrd. ; Acanthonotozomella oatesi, Brnrd. ; Gnathiphimedia sexdentata (Schell.) ; Syrrhoe psychrophila, Monod ; Epimeria excisipes, n.sp. ; Maera pfefferi, n.sp. St. 158. 21. i. 27. 53°48'S, 35°57'W. DLH. 401-41 1 m., r.: Phippsiella rostrata, n.sp.; Echiniphimedia hodgsoni (Wlkr.). St. 159. 21. i. 27. 53 52' S, 36 08' W. DLH. 160 m., r.: Ambasiopsis georgiensis, Brnrd. ;Uristes gigas, Dana; Tryphosa major, n.sp.; T. triangularis, n.sp.; T. analogica, n.sp.; Tmetonyx longitelson, n.sp.; Parharpinia sinuata, n.sp.; Gnathiphimedia mandibulars, Brnrd.; Liljeborgia longicornis, Schell.; Oediceroides calmani, Wlkr.; Epimeria excisipes, n.sp.; Eusiroides georgianus, n.sp.; Schraderia gracilis, Pfr. ; Maera pfefferi, n.sp. ; Eurystheus distichon, Brnrd. St. 160. 7. ii. 27. Near Shag Rocks, 53 43' S, 40 57' W. DLH. 177 m., gy.m. st. r.: Acidosto- mella cuHrifera, Schell. ; Stornaconfon insigne, n.sp. ; Prob'Mdes typia (Wlkr.); Liljeborgia hngiccmis Schell.; Eurystheus distichon, Brnrd. St. 162. 17. ii. 27. Off Signy Island, South Orkneys. DLH. 320 m., gn.m.: Harpinia cariniceps, n.sp. ; Epimeriella macronyx, Wlkr. St. 164. 18. ii. 27. East end of Normanna Strait, South Orkneys. NCS-T. 24-36 m.: Cardenio paurodactylus, Stebb. ; Metopella ovata (Stebb.) ; Monoculodes scabriculosus, n.sp. ; Liouvillea oadata, Chevr.; Kuphocheira setimanus, Brnrd.; Jassafalcata (Mont.). St. 165. 18-20. ii. 27. Dove Strait, Signy Island, South Orkneys. TNL. 24-36 m., from stomach of Notothenia: Cheirimedon pernor atus (Pfr.); Tryphosa kergueleni (Miers); Lepidepecreum cingulatum, n.sp.; Pontogeneiella brevicornis (Chevr.). St. 166. 19. ii. 27. SE point of Paul Harbour, Signy Island, South Orkneys. Shore collecting: Pontogeneia antarctica, Chevr. St. 167. 20. ii. 27. Off Signy Island, South Orkneys. N 7-T and N 4-T. 244-344 m., gn.m.: Harpinia cariniceps, n.sp.; Monoadodes antarcticus, n.sp.; Oediceroides calmani, Wlkr.; Eusirus antarcticus, Thorns.; E. perdentatus, Chevr.; Rhachotropis antarctica, n.sp.; Paraceradocus miersii (Pfr.) ; Eurystheus purpurescens, n.sp. St. 169. 22. ii. 27. 6o°48'S, 5i°oo'W. TYF. 1000-1 100 m., day: Vibilia antarctica, Stebb.; Cyllopus lucasii, Bate. St. 170. 23. ii. 27. Off Cape Bowles, Clarence Island. 6i° 25' S, 53 46' W. DLH. 342 m., r. : Shackletonia robusta, Brnrd. ; Waldeckia obesa (Chevr.) ; Aristias antarctiais, Wlkr. ; A. collinus, n.sp. ; Ambasiopsis uncinata, n.sp.; Tryphosella albina, n.sp.; Tryphosa major, n.sp.; Tmetonyx carinata (Schell.); Allogaussia navicula, n.sp.; A. lobata, n.sp.; Ampelisca hemicryptops, Brnrd.; Byblis antarctica, Schell.; Haploops securiger, Brnrd. ; Leucothoe spinicarpa (Abildg.); Gnathiphimedia sex- dentata (Schell.); Echiniphimedia hodgsoni (Wlkr.); Liljeborgia lo?igicomis, Schell.; Syrrhoe nodulosa, n.sp.; Syrrhoites anaticauda, Brnrd.; Clarencia chelata, Brnrd. ; Chosroes decoratus, n.sp. ;Oradarea impressicauda, n.sp. ; Austropleustes cuspidatus, Brnrd. ; Epimeria macrodonta, Wlkr. f. similis, Chevr. ; E. inermis, Wlkr.; E. excisipes, n.sp.; Epimeriella walked, Brnrd.; Parepimeria crenulata, Chevr.; P. crenulata, Chevr. var. miothele n.; Lepechinella cetrata, n.sp.; Eusirus perdentatus, Chevr.; Eusiroides georgianus, n.sp.; Rhachotropis antarctica, n.sp.; Eurystheus serricrus, n.sp.; Podoceropsis elephantis, n.sp.;Jassa ingens (Pfr.); Pseuderichthonius gaussi, Schell. STATION-LIST 13 St. 172. 26. ii. 27. Off Deception Island, South Shetlands. 62 59' S, 6o° 28'W. DLH. 525 m., r. : Waldeckia obesa (Chevr.) ; Oradarea tricarinata, n.sp. St. 173. 28. ii. 27. Port Foster, Deception Island, South Shetlands. NCS-T. 5-60 m. : Cheiri- medon femoratus (Pfr.); Orchomenella rossi (Wlkr.); Monoculodes scabriculosus, n.sp.; Oradarea edentata, n.sp.; Pontogeneiella brevicornis (Chevr.); Prostebbingia gracilis (Chevr.); Paramoera walkeri (Stebb.) ; P. edouardi, Schell. St. 174. 28. ii.-2. iii. 27. Deception Island, South Shetlands. TNL. 5-10 m. : Cheirimedon femoratus (Pfr.); Tryphosa kergueleni (Miers); Orchomenella rotundifrons, n.sp.; Bovallia gigantea, Pfr. ; Eurymera monticulosa, Pfr. St. 175. 2. iii. 27. Bransfield Strait, South Shetlands. 63 17' S, 59 48' W. DLH. 200 m., m. st. g., night: Kerguelenia palpalis, n.sp.; Aristias collinus, n.sp.; Uristes gigas, Dana; Tryphosa major, n.sp.; T. adarei, Wlkr.; Allogaussia naviada, n.sp.; Orchomenella charcoti (Chevr.); Anda- niotes linearis, n.sp.; Ampelisca hemicryptops, Brnrd. ; Heterophoxus trichosus, n.sp.; Parharpinia obliqua, n.sp.; Leucothoe spinicarpa (Abildg.) ; Iphimediella margtteritei, Chevr.; /. bransfieldi, n.sp.; Gnathiphimedia sexdentata (Schell.) ; Echiniphimedia hodgsoni (Wlkr.) ; Monoculodes antarcticus, n.sp. ; Tironantarcticus, n.sp. ; Syrrhoites anaticauda, Brnrd. ; Liouvilleaoculata, Chevr. ;Oradarea tricarinata, n.sp. ; Epimeria macrodonta, Wlkr. f. similis, Chevr. ; E. inermis, Wlkr. ; E. excisipes, n.sp. ; Parepimeria crenulata, Chevr. ; Melphidippa antarctica, Schell. ; Eusirus antarcticus, Thorns. ; Eusiroides georgianus, n.sp. ; Rhachotropis antarctica, n.sp. ; Prostebbingia gracilis (Chevr.) ; Jassa ingens (Pfr.) ; Pseuderich- thonius gaussi, Schell. ; Aeginoides gaussi, Schell. St. 177. 5. iii. 27. 27 miles SW of Deception Island, South Shetlands. DLH. 1080 m., m. cs.st. : Lepidepecreoides xenopus, Brnrd.; Ampelisca bransfieldi, n.sp.; Parepimeria major, n.sp. St. 178. 9-10. iii. 27. Melchior Harbour, Schollaert Channel, Palmer Archipelago. TNL. 17m.: Orchomenella rossi (Wlkr.). St. 179. 10. iii. 27. Melchior Island, Schollaert Channel, Palmer Archipelago. DS. 4-10 m., r. : Cheirimedon femoratus (Pfr.); Pariphimedia integricauda, Chevr.; Bovallia gigantea, Pfr.; Eurymera monticulosa, Pfr. ; Pontogeneia antarctica, Chevr. ; Prostebbingia gracilis (Chevr.) ; Djerboa furcipes, Chevr. ; Jassa ingens (Pfr.). St. 180. 11. iii. 27. Off Gand Island, Schollaert Channel, Palmer Archipelago. DLH. 160 m., m. st. : Ampelisca eschrichtii, Kroy. ; Eusirus per dentatus, Chevr. N 7-T. 160-330 m., m. st. : Oediceroides calmani, Wlkr. ; Parathemisto gaudichaudii (Guer.). St. 181. 12. iii. 27. Schollaert Channel, Palmer Archipelago. N 7-T and N 4-T. 160-335 m., m. : Lepidepeaeoides xenopus, Brnrd. ; Orchomenella rossi (Wlkr.) ; Ampelisca hemicryptops, Brnrd. ; Byblisoides juxtacornis, Brnrd. ; Harpinia cariniceps, n.sp. ; Nicippe unidentata, n.sp. ; Monoculodes antarctica, n.sp. ; Oediceroides calmani, Wlkr. ; Syrrhoe nodulosa, n.sp. ; Epimeria macrodonta, Wlkr. f. macrodonta and f. similis ; Eusirus antarcticus, Thorns. ; E. perdentatus, Chevr. ; Rhachotropis ant- arctica, n.sp. St. 182. 14. iii. 27. Schollaert Channel, Palmer Archipelago. N 4-T. 278-500 m., m. : Nicippe unidentata, n.sp.; Monoculodes antarcticus, n.sp.; Oediceroides calmani, Wlkr.; Syrrhoe nodulosa, n.sp. ; Epimeria macrodonta, Wlkr. f. similis, Chevr. ; Epimeriella walkeri, Brnrd. ; Eusirus antarcticus, Thorns.; Rhachotropis antarctica, n.sp.; Podocerus septemcarinatus, Schell. St. 184. 15-16. iii. 27. Fournier Bay, Anvers Island, Palmer Archipelago. TNL. 36 m. : Waldeckia obesa (Chevr.) ; Orchomenella rossi (Wlkr.). St. 186. 16. iii. 27. Fournier Bay, Anvers Island, Palmer Archipelago. DLH. 295 m., m. : Ampelisca hemictyptops, Brnrd. ; Byblisoides juxtacornis, Brnrd. ; Harpinia cariniceps, n.sp. ; Eusirus perdentatus, Chevr. I4 DISCOVERY REPORTS St. 187. 18. iii. 27. Neumayr Channel, Palmer Archipelago. DLH. 259 m., m. : Ampelisca eschrichtii, Kr6y.; A. hemicryptops, Brnrd. ; Anchiphimedia dorsalis, Brnrd. ; Monoculodes antarcticus, n.sp. ; Rhachotropis antarctica, n.sp. St. 189. 21-23. iii. 27. Port Lockroy, Palmer Archipelago. TNL. 7 m.: Orchomenella rossi (Wlkr.). 23-24. iii. 27. TNL. 70 m. : Waldeckia obesa (Chevr.); Orchomenella rossi (Wlkr.). St. 190. 24. iii. 27. Bismarck Strait, Palmer Archipelago. DLH and NRL. 90-130 m., st. m. r. : Cheirimedon femoratus (Pfr.) ; Andaniotes linearis, n.sp. ; Ampelisca hemicryptops, Brnrd. ; Leucothoe spinicarpa (Abildg.) ; Acanthonotozomella oatesi, Brnrd. ; Gnathiphimedia sexdentata (Schell.) ; Echini- phimedia hodgsoni (Wlkr.); E. echinata (Wlkr.); Pardalisca abyssoides, n.sp.; Eusirus perdentatus, Chevr. ; Eurystheus purpurescens, n.sp. ; Cerapas oppositas, n.sp. ; Podocerus septemcarinatus, Schell. ; DLH. 315 m., m. r. : Gnathiphimedia sexdentata (Schell.); Oediceroides calmani, Wlkr.; Epimeria excisipes, n.sp. ; Eusirus perdentatus, Chevr. ; Rhachotropis antarctica, n.sp. ; Pontogeneiella longi- cornis (Chevr.). St. 195. 30. iii. 27. Admiralty Bay, King George Island, South Shetlands. 62 07' S, 58 28' W. N 7-T and N 4-T. 391 m., m. st. : Waldeckia obesa (Chevr.); Harpinia cariniceps, n.sp.; Hetero- phoxus videns, Brnrd. ; Proboloides antarcticus, Wlkr. ; Panoploeajoubini, Chevr. ; Liljeborgia longicornis, Schell. ; Oediceroides macrodactylus, Schell. ; Syrrhoe nodulosa, n.sp. ; Epimeria excisipes, n.sp. ; Parepi- meria crenulata, Chevr. var. miothele n. ; Eusirus antarcticus, Thorns. ; E. perdentatus, Chevr. ; Aeginoides gaussi, Schell. St. 196. 3. iv. 27. Bransfield Strait, South Shetlands. 62 17' S, 58 21' W. N 70. 720 m., m. di.oz. : Urothoides oniscoides, n.sp. St. 197. 3. iv. 27. Bransfield Strait, South Shetlands. 62 27' S, 58 11' W. N 70 V. 750-500 m., day : Cyphocaris richardi, Chevr. St. 198. 3. iv. 27. Bransfield Strait, South Shetlands. N 100 H. 76 m., night: Cyphocaris richardi, Chevr. St. 202. 5. iv. 27. Bransfield Strait, South Shetlands. 62 48' S, 6o° 05' W. N 100 H. 0-5 m., night : Eusirus microps, Wlkr. St. 208. 7. iv. 27. Off Livingston Island, South Shetlands. TYF. 800 (-0) m., day: Allogaussia lobata, n.sp.; Orchomenella rossi (Wlkr.) ; O. abyssorum (Stebb.); Parandania boecki (Stebb.); Halice profundi, n.sp. ; Vibilia antarctica, Stebb. ; Cyllopus magellanicus, Dana ; C. lucasii, Bate ; Parathemisto gaudichaudii (Guer.). St. 216. 18. iv. 27. Drake Strait. 58 53' S, 67 55' W. N70V. 750-500 m., day: Cystisoma jabricii, Stebb. St. 219. 21. iv. 27. Drake Strait. 57 32' S, 67 04' W. N 70 V. 750-500 m., day: Cystisoma jabricii, Stebb. St. 222. 23-24. iv. 27. St Martin's Cove, Hermite Island, Cape Horn. TNL and NRL. 30-35 m. : Amaryllis macro phthalma, Hasw. ; Tryphosa castellata, n.sp. ; Tryphosites chevreuxi, Stebb. ; Nototropis villosus (Bate); Paramoera gregaria (Pfr.); P. hermitensis, n.sp. 23. iv. 27. Shore collecting: Hyalella patagonica, Ortm. 25. iv. 27. Fresh-water lakes, 300-350 ft. : Hyalella patagonica, Ortm. St. 239. 2. vi. 27. 46 56' S, 46 03' W. N 450. 1050-1350 m., day: Cyphocaris richardi, Chevr. ; Parandania boecki (Stebb.) ; Eusiroides stenopleura, n.sp. ; Lanceola serrata, Bov. ; Cyllopus magel- lanicus, Dana; Parathemisto gaudichaudii (Guer.); Phronima sedentaria (Forsk.); Primno macropa, Guer. St. 245. 10. vi. 27. 38 20' S, 22 18' W. N 450. 1800-2000 m., day: Lanceola pacifica, Stebb. St. 250. 17. vi. 27. 36 09' S, 5 33' W. TYF. 300 (-0) m., night: Stenopleura atlantica, Stebb. ; Scina curvidactyla, Chevr.; Phronima sedentaria (Forsk.); Streetsia challengeri, Stebb. STATION-LIST 15 St. 253. 21. vi. 27. 35 06' S, 2 19' E. TYF. 1000-1050 m., day: Cyphocaris richardi, Chevr. ; C. anonyx, Boeck ; Katius obesus, Chevr. ; Parandania boecki (Stebb.) ; Lanceola serrata, Bov. St. 254. 21. vi. 27. 35°04'S, 2° 59' E. TYF. 200 (-0) m., night: Scina crassicornis (Fabr.); Phronima sedentaria (Forsk.); Phrosina semilunata, Risso; Streetsia challengeri, Stebb. St. 256. 23. vi. 27. 35° 14' S, 6° 49' E. TYF. 850-1 100 (-0) m., day : Cyphocaris richardi, Chevr. ; C. anonyx, Boeck; C. faurei, Brnrd. ; Parandania boecki (Stebb.); Synopioides macronyx, Stebb.; Stenoplenra atlantica, Stebb. ; Lanceola serrata, Bov. ; L. pacifica, Stebb. ; Scypholanceola vanhoeffeni, Wolt. ; Scina cnrvidactyla, Chevr. ; S. incerta, Chevr. ; S. borealis (Sars) ; 5. wolterecki, Wagl. ; Vibilia cultripes, Voss ; Phronima sedentaria (Forsk.). St. 257. 24. vi. 27. 35 01' S, 10° 18' E. TYF. 250 (-0) m., night: Stenoplenra atlantica, Stebb. ; Primno macropa, Guer. ; Anchylomera blossevillei, M. Edw. ; Brachyscelus crusculum, Bate. St. 259. 26. vi. 27. 34° 59' S, 16 39' E. TYF. 170-250 (-0) m., night : Scina crassicornis (Fabr.) ; Paraphronima crassipes, Claus. St. 266. 21. vii. 27. 29° 34' S, 14 24' E. TYF. 200 (-0) m., night: Stenoplenra atlantica, Stebb. ; Scinaoedicarpus, Stebb. ; Paraphronima gracilis, Claus ; Phronima pacifica, Streets ; Phrosina semilunata, Risso ; Primno macropa, Guer. ; Eupronoe minuta, Claus ; Streetsia challengeri, Stebb. St. 267. 23. vii. 27. 24 31' S, 12 15' E. TYF. 450-550 (-0) m., night: Cyphocaris challengeri, Stebb. ; Scina cnrvidactyla, Chevr. ; Brachyscelus crusculum, Bate. N 100 B. 1 17-0 m., night : Scina cnrvidactyla, Chevr. ; Phrosina semilunata, Risso. St. 268. 25. vii. 27. 18 37' S, io° 46' E. TYF. 100-150 (-0) m., night : Scina crassicornis (Fabr.) ; Vibilia viatrix, Bov. ; Vibilia sp. ; Oxycephalus clausi, Bov. ; Platyscelus ovoides (Claus) ; P. armatus (Claus); P. serratulus, Stebb. N 100 B. 73-0 m., night: Vibilia armata, Bov.; V. cultripes, Voss; Paraphronima crassipes, Claus ; Phronima sedentaria (Forsk.) ; Oxycephalus clausi, Bov. St. 270. 27. vii. 27. 13 58' S, 1 1° 43' E. N 100 B. 126-0 m., night : Scina cnrvidactyla, Chevr. TYF. 200 (-0) m., night: Scina cnrvidactyla, Chevr. ; Vibilia viatrix, Bov. ; Oxycephalus piscator, M. Edw. St. 273. 31. vii. 27. 9 38' S, 12 42' E. TYF. 200-230 (-0) m., night: Cacao lacteus, Brnrd. ; Scina crassicornis (Fabr.); Paraphronima crassipes, Claus; Phronima sedentaria (Forsk.); Phrosina semilunata, Risso; Brachyscelus crusculum, Bate; B. globiceps (Claus); Streetsia challengeri, Stebb. St. 276. 5. viii. 27. 5° 54' S, n°i9'E. N 100 B. 110-om., night: Scina crassicornis (Fabr.). TYF. 1 50 (-0) m., night : Scina cnrvidactyla, Chevr. ; Cystisoma fabricii, Stebb. ; Prono'e capito, Guer. ; Parapronoe crustulum, Claus ; Brachyscelus crusculum, Bate ; Platyscelus inermis (Claus). St. 281. 12. vii. 27. oo° 46' S, 5 49' E. TYF. 850-950 (-0) m., day: Cyphocaris anonyx, Boeck; Metacyphocaris helgae, Tatt. ; Lanceola pacifica, Stebb. ; Scypholanceola vanhoeffeni, Wolt. ; Scina crassicornis (Fabr.) ; S. cnrvidactyla, Chevr. ; S. borealis (Sars) ; Vibilia cultripes, Voss ; Cystisoma pellucidum (W. Suhm) ; C. fabricii, Stebb. ; Phronima sedentaria (Forsk.) ; Thamneus platyrhynchus, Stebb. ; Oxycephalus piscator, M. Edw. ; Streetsia challengeri, Stebb. St. 282. 12. viii. 27. i° 11' S, 5°38'E. TYF. 300 (-0) m., night: Rhabdosoma whitei, Bate. St. 283. 14. viii. 27. Off Annobon, Gulf of Guinea. DLH. 77 m., day -.Phrosina semilunata, Risso. St. 284. 15. viii. 27. 2 13' S, 1° 52'E. N100B. 71-0 m., night -.Lanceola sayana, Bov.; Phrosina semilunata, Risso ; Oxycephalus clausi, Bov. St. 285. 16. viii. 27. 2 43' S, oo° 56' W. N450. 125-175 (-o)m., night: Cyphocaris faurei, Brnrd. ; Lanceola sayana, Bov. ; Scina crassicornis (Fabr.) ; Vibilia cultripes, Voss ; Phronima sedentaria (Forsk.) ; P. curvipes, Voss ; Phrosina semilunata- Risso ; Parapronoe crustulum, Claus ; Oxycephalus clausi, Bov.; Streetsia challengeri, Stebb.; Rhabdosoma whitei, Bate; Platyscelus ovoides (Claus); P. armatus (Claus). St. 286. 17. viii. 27. 3 06' S, 3 53' W. N 70 B. 102-0 m., night: Lanceola sayana, Bov. TYF. 125 (-0) m., night: Lanceola sayana, Bov.; Scina crassicornis (Fabr.); Phrosina semilunata, Risso; i6 DISCOVERY REPORTS Paraprono'e crustulum, Claus ; Sympronoe parva (Claus) ; Lycaea nasuta, Claus ; Brachyscclus crusculum, Bate ; Oxycephalus clausi, Bov. ; Streetsia steenstrupi, Bov. St. 287. 19. viii. 27. 2° 49' S, 9°25'W. TYF. 800-1000 (-0) m., night: Cyphocaris anonyx, Boeck ; Metacyphocaris helgae, Tatt. ; Parandania boecki (Stebb.) ; Mimonecteola tnacronyx, n.sp. ; Lanceola pacifica, Stebb. ; Scypholanceola vanhoeffeni, Wolt. ; Parascina chevreusi, Pirl. ; Cystisoma fabricii, Stebb.; Phronima pacifica, Streets; Phrosina semilunata, Risso; Oxycephalus clausi, Bov.; Rhabdosoma zvhitei, Bate. N 100 B. 124-0 m., night : Scina crassicornis (Fabr.) ; Paraphronima crassipes, Claus ; Paraprono'e crustulum, Claus ; Oxycephalus clausi, Bov. St. 288. 21. viii. 27. oo° 56' S, 14 08' W. TYF. 250 (-0) m., night: Cyphocaris faurei, Brnrd. ; Katius obesus, Chevr. ; Lanceola sayana, Bov. ; Parascina chevreusi, Pirl. ; Pronoe capito, Guer. ; Streetsia challengeri, Stebb.; Rhabdosoma zvhitei, Bate; R. armatum (M. Edw.); Platyscelus ovoides (Claus). N ioo B. 73-0 m., night: Scina crassicornis (Fabr.); Phronima curvipes, Voss; Oxycephalus clausi, Bov.; Rhabdosoma zvhitei, Bate; R. armatum (M. Edw.). St. 289. 23-24. viii. 27. 3 04' N, 16 52' W. TYF. 125-225 (-0) m., night : Rhabdosoma zvhitei, Bate. St. 290. 24. viii. 27. 3° 25' N, 16° 50' W. TYF. 100 (-0) m., day: Scina marginata, Bov.; Phronima colletti, Bov. ; Paraprono'e crustulum, Claus ; Oxycephalus clausi, Bov. ; Streetsia porcellus (Claus); Rhabdosoma zvhitei, Bate. St. 292. 24. viii. 27. 4 03' N, 16 51' W. TYF. 100-180 (-0) m., day: Rhabdosoma zvhitei, Bate. St. 294. 25. viii. 27. 4 33' N, 16 52' W. N 70 B. 101-0 m., night: Lanceola sayana, Bov. TYF. 100-150 (-0) m., night: Pronoe capito, Guer.; Oxycephalus clausi, Bov.; Rhabdosoma zvhitei, Bate; Platyscelus ovoides (Claus). St. 295. 25. viii. 27. 5 30' N, i7°45'W. TYF. 2500-2700 (-0) m., day: Cyphocaris anonyx, Boeck; Scina rattrayi, Stebb.; Cystisoma pellucidum (W. Suhm); Pronoe capito, Guer.; Streetsia challengeri, Stebb. St. 296. 26. viii. 27. 8° 12' N, i8°49'W. TYF. 450-500 (-0) m., night: Cyphocaris faurei, Brnrd.; Metacyphocaris helgae, Tatt.; Scina crassicornis (Fabr.); Paraphronima crassipes, Claus; Phronima curvipes, Voss ; Phronimella elongata (Claus) ; Pronoe capito, Guer. ; Paraprono'e clausoides, Stebb. ; Brachyscelus crusculum, Bate ; Oxycephalus clausi, Bov. ; Streetsia challengeri, Stebb. ; Leptocotis tenuirostris (Claus); Rhabdosoma zvhitei, Bate. St. 297. 28. viii. 27. i2°o8'N, 20°53'W. TYF. 200-300 (-0) m., night: Cystisoma fabricii, Stebb. ; Phronima sedentaria (Forsk.) ; Phrosina semilunata, Risso ; Primno macropa, Guer. ; Rhabdosoma zvhitei, Bate; Platyscelus biennis (Claus). N 100 B. 163-0 m., night: Euprono'e maculata, Claus; Rhabdosoma zvhitei, Bate. St. 298. 29. viii. 27. 13° 01' N, 21 34' W. TYF. 900-1200 (-o)m., day: Lanceola aestiva, Stebb. ; Vibilia cultripes, Voss; Hyperia spinigera, Bov. ; Platyscelus ovoides (Claus). R.R.S. 'WILLIAM SCORESBY' 12. ix. 26. Walvis Bay, South-west Africa. LH. 4-57 m., from stomach of Trig/a capensis: Ampelisca palmata, Brnrd. ; Melita suhcluhita, Schell. ; Lcmbos hypacanthus, Brnrd. 5. x. 26. Hoetjes Bay, Saldanha Bay, South Africa. LH. S m., from stomach of Trig/a capensis: Liljeborgia epistomata, n.sp. NH. o m., from Medusae: Hoploplcon medusarum, n.sp.; Hyperia galba, Mont. St. WS 25. 17. xii. 26. Undine Harbour, South Georgia. BTS. 18-27 m -> m - s - : Paralysianopsis odhneri, Schell.; Tryphosa triangularis, n.sp.; T. analogica, n.sp.; Orchomenella acanthurus (Schell.); Ileterophoxus videns, Brnrd. ; Parharpinia rotund if ions, n.sp. ; Oediceroides calmani, Wlkr. ; Oradarea tridentata, n.sp.; Eusiroides georgianus, n.sp.; Pontogeneiella longicornis (Chevr.); Djerboa furcipes, Chevr.; Schraderia gracilis, Pfr. ; Haplocheira barbimanus (Thorns.). STATION-LIST 17 St. WS 27. 19. xii. 26. 53 55' S, 38 01' W. N 100 H. 107 m. (bottom 80 m., g.) : Acidostomella cultrifera, Schell. ; Leucothoespinicarpa (Abildg.) ; Colomastix fissilingua, Schell. ; Polycheria antarctica (Stebb.). St. WS 33. 21. xii. 26. 54 59' S, 35° 24' W. N 100 H. 130 m. (bottom 135 m., gy.m. St.): Acidostomella cultrifera, Schell.; Lepidepecreella ovalis, n.sp. ; Lepidepecreoides xenopus, Brnrd. ; Orchomenella acanthurus (Schell.); Haploops securiger, Brnrd.; Acanthonotozomella oatesi, Brnrd.; Gnatliipliimedia mandibularis, Brnrd. ; Oediceroides calmani, Wlkr. ; Methalimedon nordenskjoldi, Schell. ; Tiron antarcticus, n.sp. ; Epimeria excisipes, n.sp. ; E. puncticulata, Brnrd. ; Haplocheira barbimanus (Thorns.) ; Caprellinoides mayeri (Pfr.). St. WS 38. 22-23. xii. 26. 54° OI 'S, 35° 14' W. N 100 H. 53 m., night: Orchomenella rossi (Wlkr.). N 100 H. 0-5 m., night: Vibilia antarctica, Stebb.; Cyllopus magellanicus, Dana; Para- t/iemisto gaudichaudii (Guer.). St. WS 53. 11-12. i. 27. From 53 42' S, 37° 12' W to 53 29' S, 37 13' W. N 100 H. 0-5 m., night: Uristes gigas, Dana; Phoxocephalus coxalis, n.sp. St. WS 56. 14. i. 27. Larsen Harbour, Drygalski Fjord, South Georgia. NH. 2 m., kelp roots: Bovallia gigantea, Pfr. ; Pontogeneiella brevicornis (Chevr.) ; Schraderia gracilis, Pfr. St. WS 62. 19. i. 27. Wilson Harbour, South Georgia. BTS. 26-83 m. : Paraperiocidodes brevi- manus, Brnrd.; Monoculodes scabriculosus, n.sp.; Djerboa furcipes, Chevr. St. WS 69. 22. ii. 27. 52 19' S, 52 11' W. N 70 H. 0-5 m., night: Parathemisto gaudichaudii (Guer.). St. WS 71. 23. ii. 27. 6 miles N 6o° E of Cape Pembroke, East Falkland Island. OTC. 82 m., s. : Amaryllis macrophthalma, Hasw. ; Tryphosites chevreuxi, Stebb.; Haplocheira robusta, n.sp. St. WS 72. 5. iii. 27. 50 07' S, 57 34' W. OTC and N 4-T. 95 m., s. sh. : Chosroes incisus, Stebb. ; Parathemisto gaudichaudii (Guer.). St. WS 76. 11. iii. 27. 51° 00' S, 62° 02' W. DC. 207 m., f.d.s. : Urothoe falcata, Schell. St. WS 79. 13. iii. 27. 51 01' S, 64 59' W. N 7-T. 132-13 1 m., f.d.s., night: Atyloella dentata, n.sp. St.WS8i. 19. iii. 27. 8 miles N 1 i°W of North Island, West Falkland Island. N 7-T. 81-82 m., s. : Epimeria fasciata, n.sp. St. WS 85. 25. iii. 27. 8 miles S 66° E of Lively Island, East Falkland Island. OTC. 79 m., s. sh. : Amaryllis macrophthalma, Hasw.; Lysianassa falklandica, n.sp.; Iphimediella nodosa (Dana); Epimeria fasciata, n.sp.; Haplocheira robusta, n.sp. St. WS 86. 3. iv. 27. 53 53' S, 6o° 34' W. OTC. 151-147 m., s. sh. st. : Epimeria fasciata, n.sp.; Haplocheira robusta, n.sp. St. WS 88. 6. iv. 27. 54 00' S, 64 57' W. OTC. 1 18 m., s. sh. st. : Ampelisca statenensis, n.sp. ; Parharpinia sinuata, n.sp.; Eusirus antarcticus (Thorns.). St. WS 89 1 . 7. iv. 27. 9 miles N 21 E of Arenas Point Light, Tierra del Fuego. N 4-T. 23-21 m., m. g. st. : Nototropis villosus (Bate) ; Parathemisto gaudichaudii (Guer.). St. WS 92. 8. iv. 27. 51 58' S, 65 01' W. N 7-T. 145-143 m., f.d.s. st. : Tryphosites chevreuxi, Stebb. ; Chosroes incisus, Stebb. St. WS 95. 17. iv. 27. 48 58' S, 64 45' W. TYF. 30 (-0) m., day: Cyllopus magellanicus, Dana; Hyperia galba, Mont. ; Parathemisto gaudichaudii (Guer.) ; Phronima sedentaria (Forsk.). St. WS 96. 17. iv. 27. 48 00' S, 64 58' W. OTC. 96 m., f.d.s. : Phoxocephalopsis zimmeri, Schell. St. WS 97. 18. iv. 27. 49 00' S, 6i° 58' W. OTC. 146-145 m., s. g. st. : Lysianassa falklandica, n.sp. 1 Wrongly plotted in Discovery Reports, vol. I, Station List, pi, iv. rt DISCOVERY REPORTS St. WS 99. 19. iv. 27. 49 42' S, 59 14' W. OTC. 251-225 m., f.d.s., dawn, from stomach of Merluccius: Parathemisto gaudichaudii (Guer.). St. WS105. 24. iv. 27. 48 50' S, 64°24'W. N100H. 101 m., day: Phronima sedentaria (Forsk.). St. WS 123. 8-9. vi. 27. Gough Island. Shore collecting: Paramoera tristanensis, n.sp. ; Allorclwstes sp. MARINE BIOLOGICAL STATION St. MS 2. 11. ii. 25. 2* cables E of Hope Point, East Cumberland Bay, South Georgia. NC 50 H. 15 m., day: Hyperiella antarctica, Bov. St. MS 6. 12. ii. 25. East Cumberland Bay, South Georgia. BTS. 24-30 m. : Oradarea tridentata, n.sp.; Schraderia gracilis, Pfr. St. MS 10. 14. ii. 25. East Cumberland Bay, South Georgia. BTS. 26-18 m. : Bovallia gigantea, Pfr. ; Pontogeneiella longicornis (Chevr.) ; Djerboafurcipes, Chevr. ; Schraderia gracilis, Pfr. ; Parajassa georgiana, Schell. St. MS 14. 17. ii. 25. Off Sappho Point, East Cumberland Bay, South Georgia. DS. 190-nom. : Caprellinoides tristanensis, Stebb. St. MS 22. 9. iv. 25. i*3 miles N of Dartmouth Point, East Cumberland Bay, South Georgia. NC 50 V. 40-0 m. : Pagetina genarum, Brnrd. ; Hyperiella antarctica, Bov. St. MS 25. 13. iv. 25. East Cumberland Bay, South Georgia. BTS. 36 m.: Eusiroides georgianus, n.sp. NC 50 H. 10 m., day: Hyperiella antarctica, Bov. St. MS 26. 15. iv. 25. East Cumberland Bay, South Georgia. NC 50 H. 10 m., day: Hyperiella antarctica, Bov. St. MS 30. 30. iv. 25. East Cumberland Bay, South Georgia. NC 50 V. 40-0 m., day: Vibilia antarctica, Stebb. ; Hyperoche medusariim (Kroy.). St. MS 32. i.v. 25. East Cumberland Bay, South Georgia. BTS. 40 m.: Djerboafurcipes, Chevr. NC 50 H. 0-5 m., day: Primno macropa, Guer. St. MS 36 B. 14. x. 25. King Haakon Bay, South Georgia. NHS. o m., day: Parathemisto gaudichaudii (Guer.). St. MS 39. 25. x. 25. King Haakon Bay, South Georgia, to 3 miles S of Undine Harbour. NHS. o m., day: Parathemisto gaudichaudii (Guer.). St. MS 40. 25. x. 25. f mile S of Cape Pariadin to 5 miles W of Welcome Island, South Georgia. NHS. o m., night: Hyperiella antarctica, Bov. St. MS 62. 24. ii. 26. East Cumberland Bay, South Georgia. BTS. 31-40 m. Orchomenella acanthurus (Schell.). St. MS 63. 24. ii. 26. East Cumberland Bay, South Georgia. BTS. 23 m. : Parepimeria crenulata, Chevr. ; Paradexamine fissicauda, Chevr. St. MS 64. 24. ii. 26. i-8 miles SE by S of King Edward Point Light, East Cumberland Bay, South Georgia. DS. 7-15 m.: Polycheria antarctica (Stebb.). St. MS 65. 28. ii. 26. East Cumberland Bay, South Georgia. BTS and NCS-T. 39 m. : Cardenio paurodactylus, Stebb.; Djerboafurcipes, Chevr.; Paradexamine fissicauda, Chevr. St. MS 66. 28. ii. 26. East Cumberland Bay, South Georgia. NCS-T. 18 m. : Monoculodes scabriculosus, n.sp.; Oediceroides calmani, Wlkr. ; Paradexamine fissicauda, Chevr. CLASSIFICATION 19 St. MS 67. 28. ii. 26. East Cumberland Bay, South Georgia. BTS. 38 m. : Cheirimedon fcmoratus (Pfr.); Gitanopsis antarctica, Chevr. ; Metopoides parallelocheir (Stebb.); Thaumatelson nasutum, Chevr. ; T. cultricauda, n.sp. ; Monoculodes scabriculosus, n.sp. ; Oediceroides calmani, Wlkr.; Oradarea bidentata, n.sp.; Pontogeneiella longicornis (Chevr.); Prostebbingia gracilis (Chevr.); Djerboa furcipes, Chevr. ; Schraderia gracilis, Pfr. St. MS 68. 2. iii. 26. East Cumberland Bay, South Georgia. [N 200. 200-0 m. sic on label.] Orchomenella rossi (Wlkr.). NRL and NCS. 220-247 m. : Orchomenella macronyx, Chevr. ; Para- perioculodes brevimanus, Brnrd. ; Oradarea tridentata, n.sp. St. MS 71. 9. iii. 26. East Cumberland Bay, South Georgia. BTS and NCS-T. 110-60 m. : Aristias antarcticus, Wlkr.; Leucothoe spinicarpa (Abildg.) ; Iphimediellamargueritei, Chevr.; Gnathi- phimedia mandibular is, Brnrd.; Echiniphimedia hodgsoni (Wlkr.); Halice profundi, n.sp.; Monoculodes scabriculosus, n.sp.; Oediceroides calmani, Wlkr.; Oradarea bidentata, n.sp.; Epimeria puncticulata, Brnrd.; Par epimeria crenulata, Chevr.; Eusiroides georgianus, n.sp.; Prostebbingia gracilis (Chevr.); Djerboa furcipes, Chevr.; Polycheria antarctica (Stebb.); Cerapus oppositus, n.sp. St. MS 74. 17. iii. 26. East Cumberland Bay, South Georgia. NCS and BTS. 22-40 m. : Thauma- telson nasutum, Chevr.; Monoculodes scabriculosus, n.sp.; Oradarea tridentata, n.sp.; O. bidentata, n.sp.; Prostebbingia gracilis (Chevr.); Djerboa furcipes, Chevr.; Paradexatnine fissicauda, Chevr. St. MS 82. 6. ix. 26. Off Salamander Point, Saldanha Bay, South Africa. BTS. 4 fms. (7-14 m.) : Iphimedia capicola, n.sp.; Panoploea excisa, n.sp.; Paramoera capensis (Dana). Examples of Cyamidae were collected at South Georgia, South Shetlands, Saldanha Bay, Durban, and at 14 45' N, 18 24' W. GENERAL REMARKS AND OBSERVATIONS CLASSIFICATION It is not always easy to steer a middle course between "lumping" and "splitting". In many modern works a noticeable tendency towards the latter is present, and there is much to be said in its favour. In cases where abundant material in all stages of growth can be obtained from well-explored areas like the European seas, it is often possible to establish an acceptable synonymy. But in a vast region like the southern hemisphere, where extremely little detailed exploration has been carried out, and we are only just starting to acquire a knowledge of the fauna, much greater caution is necessary. As a result of the study of the Discovery collection, it has been borne in upon me, to my great regret, that much of the work of the late Dr Chilton was marred by too premature an insistence on the "variability" and "wide distribution" of certain species in the Antarctic and sub-Antarctic seas. Variation should not be invoked to account for slight differences between forms from different regions. It should be determined on a large number of individuals from one locality or contiguous areas (e.g. Echiniphimedia echinata). And when determined in one form it should not be attributed by analogy, or only with the greatest caution, to another allied species or, a fortiori, genus. The recognition of this principle and the desire to avoid an increase in the number of "species " seem to be responsible for the tendency to adopt a trinomial nomenclature. It is questionable whether it is not more convenient, as often as not, to regard every 3-2 20 DISCOVERY REPORTS form or variety, unless connected with the typical form by full series of gradations, as a species. For example, the common Lysianassid Orchomenella chilensis occurs in several forms (cf. Schellenberg, 1926) in Antarctic and sub-Antarctic waters. It also occurs in South Africa in a form (f . plicata) so distinct that one may well consider it as a species ; as a species, moreover, which does not occur elsewhere so far as we yet know. But the trinomial system of recording is certainly far better and more accurate than the state- ment that O. chilensis is a variable and widely distributed species. Such a statement would entirely conceal and confuse the facts of geographical distributions. A further example of confusion caused by "lumping" is the Nannonyx kidderi "complex", which may be said to have been imposed, and to have imposed, upon all authors since 1909. A very great deal of work has yet to be done on the southern fauna before the classi- fication rests on as firm a footing as does that of the northern fauna ; and many points in the latter are still not settled. In the meantime it seems wiser to err on the side of "splitting". HISTORICAL It may be of interest to give a brief outline of the growth of our knowledge of the Amphipodan fauna of the area primarily investigated by the ' Discovery ', i.e. the South American quadrant ; for this purpose the Chilean and Patagonian coast north of 47 S lat., and also Tristan da Cunha, will be excluded. It is rather surprising that the first Amphipod to be described from this region, in fact from the Antarctic, should be a pelagic form and not a littoral form, even though it is the commonest pelagic form there. In 1825 Guerin described Themisto gandichandii ', collected near the Malouines (Falkland Islands) by Gaudichaud, who was botanist on the 'Uranie'. Gaudichaud also collected an Anchylomera {abbreviata = blossevillei M. Edw.) and a Phlias (serratus) in the course of a voyage between the Malouines and Port Jackson. These were described by Guerin in 1836. It is probable that both these species were collected in the Southern Pacific. Anchylomera has not been found in the area under discussion; and Phlias has not since been rediscovered, though Stebbing (1899, Trans. Linn. Soc. Loud., p. 417) reported a specimen from the Mediterranean which agreed with the generic characters of Phlias. Both these species, therefore, are here ignored. To the enterprise of the early French whalers we owe the important paper by Rousell de Vauzeme on Cyamus in 1834, in which are described the three species of whale louse, ovalis, erraticus, and gracilis, based on specimens collected from "whales harpooned under his own eyes" in the neighbourhood of Tristan da Cunha and the Falklands (see Stebbing, 1888, p. 155). In 1848 Milne-Edwards described the huge Amphipod Lysianassa magellanica, col- lected by D'Orbigny from the stomach of a fish caught off Cape Horn. This species has not been rediscovered in the south, though it has been identified with the Arctic HISTORICAL 21 Eurythenes gryllus . I am by no means prepared to accept this identification, as from our present knowledge of the Arctic and Antarctic faunas it seems far more likely that magellanica will prove to be a valid species (see infra, p. 58). Meanwhile the U.S. Exploring Expedition had traversed our area, and the following Amphipoda, with their equivalent modern names, were described in Dana's classic work (1852, 1853 and 1855): Stcnia magellanica Anonyx fuegiensis Uristes gigas Iphimedia nodosa Atyhts simplex Gammarus fuegiensis Orchestia scutigerula „ nitida Amphithoe brevipes Cyllopus magellanicus T/iemisto antarctica Hyperia trigona Tierra del Fuego ^ J Antarctic, stomach of fish Hermite Island >> "Feejee Islands" Tierra del Fuego >> Hermite Island Tierra del Fuego " Lagulhas Bank near Cape Horn " United, and considered species dnbiae (Stebbing, 1906) Uristes g. Iphimediella n. Pontogeneia s. Lembos f. (see Stebbing, 19 14) Talorchestia s. Orchestia n. Ampithoe b. Cyllopus m. Parathemisto gaudichaudii Probably a young P. gaudichaudii We may thus reckon that eight definite and recognized species were added to the fauna list. No further additions were made until Bate visited the Paris Museum and described in his British Museum Catalogue of Amphipoda (1862) some specimens derived from the collections made during the voyage of 'La Zelee' (1837-40). These were: Orchestia fuegensis Cyllopus danae Cyllopus lucasii Vibilia edwardsii Port Famine Near Powel Island (South Orkneys) = O. nitida, Dana = C. magellanicus, Dana = C. lucasii = V. edwardsii (see p. 264) He also recorded from the same expedition Themisto antarcticus, Dana, from 62 25' S, 58°W. In the same work Bate described two species collected at Hermite Island by the British Expedition of the 'Erebus' and 'Terror' under Sir James Clarke Ross (1839- 43) (referred to by Bate as the "Antarctic Expedition"), viz.: Atylus huxleyanus = Halirages h. „ villosus = Nototropis v. The latter has remained obscure until rediscovered by the ' Discovery. Although not collected within our area, mention may here be made of Anonyx (= Orchomenella) chilensis described by Heller in 1868 from the collections of the 'Novara'. This is a polymorphic species which is considered (Schellenberg, 1926) to include several forms which do occur in our area. In 1 87 1 Cunningham gave an account of some Amphipods collected by him during 1 Stebbing (1910 a, p. 476) included this in the South African fauna, suggesting that Dana meant to write "Cape of Good Hope". Bate records it from the "Antarctic Expedition". 22 DISCOVERY REPORTS the cruise of H.M.S. ' Nassau ' in the years 1866-9. Brief and unsatisfactory descriptions were given of the following : Allorchestes patagoniais, of which Hyalella patagonica Ortm. 191 1 may be a synonym. Atylus batei, which Stebbing (1888, p. 405) held to be synonymous with huxleyanus. Although Cunningham recorded also the latter species, I incline to Stebbing 's view. Ipliimcdia normani, a species which Stebbing rediscovered in a collection from the Falkland Islands and referred to the genus Pariphimedia. In 1887 Bovallius described Tyro (= Scina) tullbergi from off Cape Horn. There is no further record of a Scina from this area, nor has the ' Discovery' taken any. Next came the important paper by Pfeffer (1888) on the Amphipods collected by the German Transit of Venus Expedition at South Georgia in the years 1882-3. Up to this time South Georgia was terra incognita so far as concerned Amphipoda. Pfeffer de- scribed 13 species, all of which he considered as new to science. Chilton in 1913 re- examined the types and came to the conclusion that six of the species were synonymous with previously described species. From the study of the present collection I am venturing to disagree with Chilton in regard to some of these synonyms. In my opinion ten of Pfeffer 's species are to be maintained as valid, viz.: Orchomenella zschauii Paramoera gregaria Ckeirimedon femoratus Schraderia gracilis Metopoides sarsii Pontogeneia georgiana Bovallia gigantea Paraceradocus miersii Eurymera monticalosa Caprellinoides mayeri In the same year (1888), but later than Pfeffer's paper, appeared Stebbing's Chal- lenger Report, the most wonderful work yet published on the Amphipoda. That the ' Challenger ' added comparatively few species to the fauna list of our area is due to her having passed but once through Magellan Strait (January 1876) and captured specimens of Amphipods at only three stations. One of these (St. 313), however, provided nine new species. The additions to the fauna list were as follows: Acontiostoma magellanica Proboloides crenatipalmata Amaryllis macrophthalma Hasw. Seba saundersii Stebb. Metopella ovata Chosroes incisus Metopoides magellanicus Atylopsis dentata M. parallelocheir Atyloella magellanica M. compactus Hyperia gaudichaudii = galba A month after the 'Challenger,' the 'Gazelle' also passed through Magellan Strait, and at St. 47-53 a few Amphipods were collected, which, however, were not identified or reported upon (see Studer, Forschungsreise 'Gazelle', in, pp. 279 sqq., 1889). To bridge the gap between the Challenger Report and that of the First French Antarctic Expedition, we find that Mayer has recorded (in 1890) Caprella equilibra and (in 1903) C. acutifrons and nngulina, and Piperella grata. The latter, derived apparently from the same collection whence Pfeffer had already described Caprellinoides mayeri, is in my opinion only the young of C. mayeri. ARCTIC AND ANTARCTIC FAUNAS 23 Our first insight into the richness of the fauna of the more southerly portions of the area in question was provided by the results of the First French Antarctic Expedition, 'Le Francais' (1903-5). Chevreux in his report (1906) recorded nine species already known and 15 new species. Allowing for probable synonymy, I think that 17 of these two dozen species can be admitted as additions to the fauna list. In 191 1 Chevreux was able to record two species from the South Sandwich Group, an area which it is seldom possible to visit on account of the pack ice. These two are, in my opinion, synonymous with previously described species and are not reckoned here. Ortmann (Princeton University Expedition to Patagonia) in 191 1 described Hyalella patagonia, which may be the same as Cunningham's Allorchestes patagonicus . Chevreux's preliminary diagnoses of some of the Amphipods of the Second French Antarctic Expedition, the 'Pourquoi Pas? ' (1908-10), and also Chilton's account of the Amphipods of the Scottish National Antarctic Expedition, ' Scotia', appeared in 1912. Chevreux's full account appeared the following year. These two expeditions added about 24 ('Pourquoi Pas?') and 11 ('Scotia') species to the fauna list. The collections of Mr Rupert Vallentin at the Falkland Islands enabled Stebbing (1914) to add ten more species, four of which were new. In 19 14 also a pelagic Amphipod originally described from another sector of the Antarctic ( Tauria macrocephala, Dana) was recorded by Shoemaker from South Georgia. Finally Monod in his report (1926) on the " Belgica " Amphipods recorded five species from the Magellan Strait area, and seven from about 87 W long. Some of the speci- mens, being juveniles, were not referred to definite species. Reckoning these doubtful species, approximately 120 species were thus known when the Discovery Investigations were beginning. 1 The first two years' cruising of the 'Discovery' and the 'William Scoresby' has re- sulted in doubling the number of species on the fauna list. Approximately 242 species are now known. ARCTIC AND ANTARCTIC FAUNAS One notable result of the Discovery Investigations has been the finding of further evidence of the similarity of the northern and southern faunas. Chevreux (1913) noted 11 families of Gammaridea, and also the Caprellidae, as absent from Antarctic waters. Representatives of four of these families, and of the Caprellidae, were collected by the 'Gauss'. The 'Terra Nova' obtained a Lafystiid. Consequently there are only a few of the smaller families like the Stenothoidae, Cressidae, Anamixidae, Ingolfiellidae, Argissidae, etc., which are not yet known to be represented in the Antarctic fauna. Though the ' Discovery ' has not brought back representatives of any known family not previously recorded from Antarctic or sub- Antarctic waters, she has discovered representatives of a new family, Pagetinidae, and a new genus which may also require 1 Schellenberg's 1931 report on the Swedish Antarctic Expedition material not included. 24 DISCOVERY REPORTS to be put in a family of its own. Moreover Bate's Atylus villosus has been rediscovered, so that the Atylidae are now known to be definitely present in the Antarctic. In regard to genera the 'Discovery' has added the following to the Antarctic fauna list: Byblis, Haploops, Pardalisca, Nicippe, Halice, Tiron, Maera, Megamphopus , Podoceropsis . Evidence of the similarity of the northern and southern faunas is thus accumulating rapidly. Though it may still be correct to say that the southern area lacks certain families or genera, the balance may soon tilt the other way, and it will be the northern area which will be noted for its deficiencies. For the abundance and richness of the Antarctic fauna is being confirmed to an ever increasing degree by every successive expedition. ' '•.. / / / / / a n© • Parathemisto gaudichaudii a Vibilia antarctica o Cyllopus mage/lan/cus © Cyllopus lucasii Fig. i. Chart showing distribution of the four commonest pelagic Amphipods. The relative abundance is indicated approximately by the size of the signs. For details of the South Georgia area see Fig. 2. The South Orkney records are from Bate (1862). (Isobaths approximate only.) As examples of the wealth of species in some localities,, the lists of species at certain stations may be mentioned. Around South Georgia St. 42 and St. 140 both produced 25 species, St. 123 28 species, and St. 144 29 species. Off Clarence Island St. 170 pro- duced 36 species. In Bransfield Strait St. 175 produced 33 species. These are all bottom dwellers, and were captured in a single haul at each station. DISTRIBUTION It would be premature to attempt a lengthy discussion of the geographical distribution of the components of the Amphipodan fauna of the area investigated, especially in view of the further investigations now being undertaken by the ' Discovery II'. It may not be amiss, however, to deal briefly and tentatively with some of the conclusions to which the results of the Discovery (1925-7) investigations seem to point. DISTRIBUTION 25 The detailed oceanographical results have yet to be published, but it is sufficient for our purpose to note the main course of the currents and the bathymetrical features. The cold west drift current passes through Drake Strait and across the Southern Atlantic. South Georgia lies athwart its course; a fact which has very important bearings on the distribution of whale food and whales (see Hardy, Geogr.Jonrn., lxxii, Sept. 1928). The Falkland Islands lie on the northern flank of this current, and between them and the mainland of South America a warmer current flows southwards. These two currents seem to have but little influence on the pelagic Amphipods. The three most abundant pelagic species in the Discovery collection are found in both currents (cf. chart, Fig. 1), though a fourth species, Cyllopus lucasii, appears to be con- fined to the colder waters. Within the limits of the cold west drift current, the distribution of the pelagic Amphi- pods around South Georgia is noteworthy, especially as it coincides in a striking manner aX • Parathemisto gaudichaudii d Vibilia antarctica o Cyllopus magellanicus o Cyllopus lucasii a Primno macropa Fig. 2. Chart showing the stations around South Georgia at which the five commonest pelagic Amphipods were captured. (Cf. Hardy, Geogr. Journ., lxxii, Sept., 1928, figs. 4, 5.) with the distribution of Eiiphausia superba (cf. Hardy, loc. cit. Figs. 4 and 5) and is evidently due to similar ecological factors. With the exception of two captures of Parathemisto gaudichandii by members of the Marine Station, not a single pelagic Amphipod was captured on the south-west side of South Georgia ; whereas on the north-east side several species were found, some of them in great abundance (cf. chart, Fig. 2). It is true that the two vessels of the expedition did more collecting on the north-east side (cf. Discovery Reports, 1, Station list, pi. ii), but the 'William Scoresby' ran a line of stations (WS 40-52 and 63) on the south-west side with entirely negative results, so far as Amphipods are concerned. The conclusion seems warranted that the causes which Hardy {loc. cit) suggested are operative determining the distribution of Eiiphausia, are operative also in the case of the pelagic Amphipods. The same contrast in the relative abundance of Amphipods on the two sides of South Georgia is found also in the bottom fauna, though in a much less noticeable degree. 26 DISCOVERY REPORTS As regards the bottom fauna of the whole region under discussion, one outstanding feature becomes evident when we analyse its composition in the several areas. The ioo fathom (183 m.) line unites the Falkland Islands with Tierra del Fuego and the mainland, and there is considerable similarity in their faunas. These two areas are separated, however, from the more southerly groups of islands by a considerable depth of water, in Drake Strait by a depth of over 2000 fathoms, and by the sudden hydro- graphic change known as the Antarctic Convergence. That a strong contrast should be found between the shallow-water faunas on opposite sides of this channel was not surprising. It was apparent to some extent from the results of previous explorations, but the Discovery Investigations have accentuated it very considerably. As in the case of the boreal and austral faunas, so in a similar manner on a smaller scale the contrast is most marked in the species, less so in the genera, and still less so in the families; though even here there is a difference. So far as our present knowledge goes, the Atylidae and Aoridae are present in the Magellanic area (including under this term the Falkland Islands), but not in the more southerly groups of islands. On the other hand the latter area contains seven families which have no representatives in the Magellanic area ; the most important of these families being the Pardaliscidae, Tironidae and Pleustidae. As examples of genera, which are found in the Magellanic area but do not appear to extend farther south, may be mentioned Amaryllis, Lysianassa, Tryphosites, Urothoe, Halirages, Nototropis, Lembos, Stenothoe, Amphithoe, and Melita. The following genera are common to both areas, but are represented by different species in the two areas : Tryphosa castellata in Magellanic area opposed to analogica. Seba saundersii „ „ „ antarctica and other species. Colomastix castellata Iphimediella nodosa Pariphimedia normani Patioploea macrocystidis Monoculodes vallentini Chosroes incisus Epimeria acanthnrus Pontogeneia simplex Paradexamine nanus Eurystheus eurypodii Haplocheira robusta As regards the Epimeriids the fissilingua. margneritei and others. integricauda. joubini. antarcticus. decoratus. macrodonta and other species. antarctica. fissicauda. distichon and others. barbimanus. ; Terra Nova ' record of Epimeria inermis from west of the Falkland Islands appears anomalous, but is not really so, as there is a tongue of deep water running northwards between the Falkland Islands and Tierra del Fuego. 1 The ' Discovery' crossed this tongue of deep water recording depths of 578-675 m., but unfortunately secured no Amphipods (St. 227-230). Further investigation of this area might prove interesting. 1 Cf. chart in Pratjc, Beitrag zur Bodengestaltung des Atlantischen Ozeans, Centralbl. Min. Geol. Palaeont., Abt. B, No. 3, p. 129, fig. 2, 1928. BIOLOGICAL 27 Among the species which inhabit both areas there are one or two interesting cases. Widely distributed species like Lencothoe spinicarpa, jfassa falcata, and Polycheria antarctica may be ignored ; also Eusirus antarcticiis and Rhachotropis antarctica which are probably more bathypelagic than true bottom dwellers. In the same category is Parharpinia sinnata, which like most Phoxocephalids is probably pelagic at night or at certain seasons. Records of Pachychelium and the Metopids are to be used with caution, as these forms are often liable to be misidentified owing to the minuteness of the differential characters. Of particular interest, however, is the occurrence of Paramoera gregaria and Talor- chestia sciitigenda at South Georgia as well as in the Tierra del Fuego area. The former is a littoral or shallow- water form, and might conceivably have migrated before Drake Strait became the wide and deep channel it now is. But the latter is a terrestrial form and not improbably dates back to a still earlier period when the Antarctic continent — or at least South Georgia — was connected with Tierra del Fuego (v. Gregory, The Geological History of the Atlantic Ocean, Quart. Journ. Geogr. Soc, lxxxv, Pt. 2, p. cvii sqq. and maps, p. cxviii, 1929). There is a strong resemblance between the faunas of the South Shetland Islands and Palmer Archipelago on the one hand, and the Ross Sea area on the other hand, as evidenced by the Acanthonotozomatids, Epimeriids and other forms. BIOLOGICAL With a view to gaining an insight into the mutual relationships of marine organisms, it may be of interest to collect together lists of those Amphipods which were found by the 'Discovery' in the stomachs of fishes, and those which were found commensal in sponges and Ascidians. From stomach of " Perca antarctica ", Blue Fish 1 : Vibilia armata, Cyllopus magellanicus, Phronima sedentaria. From stomach of Thynmts pelamys : Phronima sedentaria. From stomach of Merluccius : Parathemisto gaudichaudii. From stomach of Nancrates ductor : Platyscelus ovoides. From stomach of Notothenia : Cheirimedon femoratus, Tryphosa kergueleni, Lepidepecrcum cingulatum, Pontogeneiella brevicornis. From stomach of skate (Psammobates) : Phoxocephalopsis zimmeri. From stomach of Trigla capensis: Ampelisca palmata, Li/jeborgia epistomata, Melita sitbchelata, Lembos hypacanthus. On or in sponges: Lettcotho'e spinicarpa, Seba antarctica, Colomastix castellata, Echiniphimedia hodgsoni, Echiniphimedia echinata, Chosroes incisus, Oradarea tridentata, Polycheria antarctica, Didymochelia spongicola. On Cephalodiscus : Podocerus septemcarinatus. On the crab Eurypodius : Eurystheus eurypodii. In branchial chamber of Ascidians : Orchomenella macronyx, Probohides porceUanus. In Medusae : Hoplopleon medusarum, Hyperia galba. 1 Probably = Seriolella velaini, Sauv., see Regan, Ann. Mag. Nat. Hist. (8), xi, p. 467, 1913. 4-2 2 8 DISCOVERY REPORTS SYSTEMATIC ACCOUNT GAMMARIDEA Family LYSIANASSIDAE Stebbing, 1906, pp. 8 and 717-721. Schellenberg, 1926, p. 239. Barnard, 1930, p. 318. Remarks. In dealing with several genera in this family the characters of the epistome plus upper lip, and the profile outline of pleon segment 4 have been regarded as of specific importance. Some other authors have assumed an extensive variability in these characters, without adducing definite proof of such variability in every case, and on this basis have attempted to lump many forms together under one name, whereby the "species" has acquired a "wide distribution". An outstanding example of this pro- cedure is the sinking of the Australian Tryphosa camelus, Stebb. as a synonym of the Norwegian T. sarsi (cf. Chilton, 1921a, p. 43). On the contrary I have found in examining the present collection very little evidence of variability. Enlarged drawings of the profiles of pleon segment 4 of several indi- viduals, if superimposed, would naturally not coincide exactly; but the essential and characteristic curve of the profile is maintained. It is thus a good specific character. One feature has not been taken into account in dealing with the more closely allied representatives of this family, viz. the surface sculpturing. The possible importance of this was not fully realized until the bulk of this report was completed and the Ponto- geneiids were being studied (infra, p. 195). I may suggest, however, that the value of this character be investigated in, e.g., the genera Orchomene, Orchomenella and Try- phosa. The Cape form of chilensis (plicata) has the surface nitidulous with scattered pits, whereas rossi has a perfectly nitidulous surface without any pits. Stebbing, 1906, p. 11. Schellenberg, 1926, p. 239. Barnard, 1930, p. 318. Genus Kerguelenia, Stebb. Kerguelenia palpalis, n.sp. Schellenberg, 1926, p. 241, fig. 2. (Kerguelenia sp., juv.) Occurrence: St. 175. South Shetlands. 1 (? $) 6 mm. 1 Remarks. This specimen seems to belong to the same species as the young specimen mentioned by Schellenberg. It has the same stout palp on the maxilliped as figured by him, the biramous 3rd uropod, and the distally expanded and lobed 2nd joint of peraeopod 3. First antenna with 6-jointed flagellum, 4-jointed accessory flagellum. Second antenna with 6-jointed flagellum. Eyes as in boreal is. 1 Except where otherwise stated, all measurements are taken from the point of the head or rostrum to the end of the telson. LYSIANASSIDAE 29 From borealis it differs in the much stouter palp of the maxilliped, the slightly more broadly rounded postero-inferior angle of pleon segment 3, and the (vertical) depth of the excavation on side-plate 4 being equal to the (vertical) depth of the backward process (in borealis, Sars, 1895, pi. xl, fig. 2, the former is greater than the latter, if the figure is a true side view and the lower parts of the side-plates are not foreshortened). Distribution. 'Gauss' winter station, 385 m. Genus Shackletonia, Brnrd. Barnard, 193 1, p. 425. Body robust. Side plates deep, 1st deeper than 2nd and 3rd, 4th large, deeply ex- cavated, 5th bilobed, posterior lobe deeper than anterior. Telson deeply cleft. Antennae (immature) short, 2nd and 3rd peduncular joints of 1st antenna very short, accessory flagellum nearly as long as flagellum. Mouth-parts rather prominent. Epistome evenly convex in front, passing into upper lip without any intervening notch or groove. Mandible elongate, cutting edge straight, molar slight, conical, palp inserted in middle of trunk just behind molar. Lobes of lower lip subacute. First maxilla slender, outer lobe with very oblique distal margin set with six strong recurved hooks, palp 2-jointed, distally narrowing to subacute apex. Second maxilla slender, inner lobe shorter than outer. Maxilliped with inner plate small, slender; outer plate large, margin entire and unarmed; palp moderate, 4-jointed. First gnathopod simple. Second gnathopod minutely chelate. Peraepods 3-5 with 2nd, 4th and 5th joints strongly expanded. Uropods 2 and 3 with peduncle stout. Accessory branchiae one on each of segments 2-5, two on segment 6. Remarks. This form has characters of both Acidostoma and Phoxostoma. The mouth- parts show the peculiar hook-like spines on the 1st maxilla only found elsewhere in Acidostoma, and which are possibly adaptations to a particular diet. On the other hand the palps of maxilla 1 and maxilliped show no degeneration. The development of the accessory branchiae is exactly like that of Waldeckia obesa and raises the question as to what systematic value these structures possess. Named in commemoration of the exploits of the late Sir Ernest Shackleton in the Antarctic regions. Shackletonia robusta, Brnrd. (Fig. 3). Barnard, 193 1, p. 425. Occurrence: 1. St. 123. South Georgia. 1 juv. 12 mm. 2. St. 170. South Shetlands. 1 immat. 28 mm. Type. Description. Body robust, tumid in middle as in Waldeckia obesa. Integument indurated, with scattered punctures extending over the peraeon, pleon, side-plates and 2nd joints of peraeopods 3-5. Head with antero-lateral angle rounded. Eyes large, reniform, wider below than above, dark. 3° DISCOVERY REPORTS Side-plate i slightly deeper than 2 and 3, rounded below, not expanded forwards; 4 deep and strongly excavate, contiguous with margin of anterior lobe of 5; posterior !obe of 5 deeper than anterior lobe, hidden below 2nd joint of peraeopod 3 ; 6 and 7 ovate, deeper than long. Pleon segment 1 with antero-inferior angle quadrate, postero-inferior angle rounded ; postero-inferior angle of segment 2 quadrate, of segment 3 shortly produced in a short acute point, margin above straight; dorsal profile of segment slightly gibbous. Telson longer than basal width, cleft to base, lobes tapering evenly to acute apices, smooth, without any spinules. Fig. 3. Shackktonia robusta, Brnrd. a. General view, punctuation indicated on segment 4. b. Profile of epistome and upper lip. c. Maxilla 1. d. Maxilliped. e. Peraeopod 5. /. Pleon segment 3 of young (St. 123). Antenna 1, 1st joint large and stout, slightly produced on inner upper apex, 2nd and 3rd joints very short, flagellum 9-jointed, accessory flagellum nearly as long as flagellum, 6-jointed. Antenna 2 slightly longer than antenna 1 , 5th joint shorter than 4th, flagellum u -jointed. Epistome convex in front, passing evenly into the upper lip, without any deep inter- vening groove or notch. Mandible elongate, cutting edge straight, with denticle at each end, oblique, secondary cutting plate and spine row obsolete, molar weak, conical, palp inserted just behind molar, 3rd joint shorter than 2nd, falcate, a comb-like row of spine setae on margin of 3rd joint and distal half of 2nd joint. Lower lip with lobes apically subacute. Maxilla 1 slender, inner lobe feeble, tipped with 1 seta and 1 setule, outer lobe strong, apex oblique, with six strong hook-like spines, followed by a comb-like row of short spinules, palp 2-jointed, 2nd joint not quite reaching apex of outer lobe, tapering distally to a subacute apex, with one minute spinule, another minute spinule LYSIANASSIDAE 3I on inner margin just below apex. Maxilla 2 slender, inner lobe shorter and narrower than outer, both tipped with setules and rather strong spine setae. Maxilliped with inner plate slender, tipped with three spines ; outer plate large, extending to middle of 3rd joint of palp, margin quite smooth and unarmed ; 4th joint of palp well developed. Gnathopod 1 simple, stout. Gnathopod 2 much more slender, 6th joint about two- thirds length of 5th, its lower apex produced in a short rounded lobe opposed to the finger. Peraeopods 1 and 2 moderately stout. Peraeopods 3-5 very stout, 2nd joints strongly expanded, especially in peraeopods 3 and 4, where they are broader than long, hind margins convex, scarcely notched, in peraeopod 5 oblong, upper and lower hind angles quadrate, hind margin gently convex, slightly notched; 4th and 5th joints also strongly expanded especially in peraeopods 3 and 4 ; anterior margins of 2nd-6th in all three peraeopods strongly armed with spines and spinules. Uropod 1 not extending beyond apex of telson, upper outer margin of peduncle strongly spinulose, rami acuminate, outer margin of outer ramus spinulose, and inner margin of inner ramus also, but to a less extent. Uropod 2 with peduncle stout, similar to uropod 1 in armature. Uropod 3 extending to apex of telson, rami ovate, apices subacute, inner margins of both rami with dense fringe of plumose setae, 2nd joint of outer ramus represented by a minute spinule. Accessory branchiae developed on segments 2-6, one on each of segments 2-5, two on segment 6. In the young specimen (St. 123) pleon segment 3 has a considerably more produced postero-inferior angle, and each lobe of telson has a minute apical spinule. The eyes are smaller and more oval. Even the type specimen shows no sign of penial processes or brood lamellae. Remarks. This form bears a close general resemblance to Waldeckia obesa, an example of which was caught in the same haul (St. 170), but the relations of the 4th and 5th side-plates and the expanded joints of peraeopods 3-5 at once distinguish it. Schellenberg( 1 928, Zool. Anz., lxxix, p. 285), in a preliminary account of Stephensenia haematopus, claims on analogy with the members of the Haustoriidae that the expansion of the joints of the last three peraeopods indicates a burrowing mode of life. Although this feature is rare in the Lysianassidae, it is not unknown, as it occurs in Acidostoma, Menigrates and Onisimus plantus ; in fact the fossorial character of peraeopods 3-5 is better developed in Acidostoma than it is in Stephensenia. If the expansion of the joints of the last three peraeopods is really indicative of fossorial habits, the present form must certainly be put in the category of burrowing species. In Acidostoma, however, the mouth-parts are considered (Sars, 1895, p. 38) to indicate a semi-parasitic mode of life. Direct observations are required rather than speculations as to the possible functions of certain features. The nature of the bottom at St. 170 is given as "rock," and at St. 123 as "grey mud." 32 DISCOVERY REPORTS Genus Acidostomella, Schell. Schellenberg, 1926 b, p. 197. As pointed out below, the possession of a 2-jointed mandibular palp as originally described must be regarded as an unconfirmed character of the genus. No accessory branchiae. Phoxostoma, Brnrd. (1925), is distinguished by the mandibular palp being set far back at the base of the trunk, the very short unguiform 4th joint of the palp of the maxilliped, and by having no groove between the upper lip and the epistome. The peculiar bulbous expansion at the base of the 2nd joint of the palp of maxilla 1 is not found in Phoxostoma, though this joint has the same stiff knife-like character as in Acidostomella. Acidostomella cultrifera, Schell. Schellenberg, 1926 b, p. 197, fig. 1. Occurrence: 1. St. 39. South Georgia. 1 $ 9 mm., 1 juv. 4-5 mm. 2. St. 160. Shag Rocks. 1 $ 8-5 mm. 3. St. WS 27. South Georgia. 2 $$ 7 mm. 4. St. WS 33. South Georgia. 1 $ 8 mm., 1 juv. 4-5 mm. Remarks. Agreeing with the 'Valdivia' specimen in all respects, except that the mandibular palp is 3-jointed. The 3rd joint is two-thirds the length of the 2nd and is setose as usual. The apex of the 2nd joint bears setae as in Schellenberg's figure, and it would seem that the absence of a 3rd joint was accidental. Inner ramus of uropod 2 constricted. Schellenberg (193 1 , p. 22) now regards this form as synonymous with Socarnoides kergueleni, Stebb. Distribution. Kerguelen, 5-10 m. Genus Acontiostoma, Stebb. Stebbing, 1906, p. 15. Acontiostoma marionis, Stebb. Stebbing, 1888, p. 709, pi. xxx and p. 714, pi. xxxi (magellanicum, = juv.). Stebbing, 1906, p. 15, fig. 4 and p. 15 (magellanicum). Stebbing, 1914, p. 356. Chilton, 1912, p. 462. Schellenberg, 193 1, p. 5. Occurrence: St. 55. Falkland Islands. 1 ? with embryos 10 mm. Remarks. The embryo has 1-2 spine setae on uropod 3 and two spines on the telson, but lacks the hump on pleon segment 4. These features and the finding of an adult marionis in the Magellanic region support the view that magellanicum should be re- garded as the young of marionis. The colour is noted as "pure white with pink antennae". This seems to show that Chilton's endeavour to identify "bright red" specimens from New Zealand with this species requires further investigation. LYSIANASSIDAE 33 The present specimen is larger than either the ' Challenger ' or the ' Scotia ' specimens. The strongly chitinized apices of the outer plates of the maxilliped are very noticeable. Distribution. Marion Island 90-135 m.; Cape Virgins 100 m.; Gough Island 100 fathoms; Falkland Islands; Kerguelen. Genus Stomacontion, Stebb. Stebbing, 1906, p. 16. Barnard, 1916, p. 109. The species described below is provisionally placed in this genus, though differing in certain respects. In other respects it combines the characters of both Acontiostoma and Stomacontion. From both it differs noticeably in the 1st gnathopod. Chilton (1912) was of opinion that Stomacontion was not generically distinct from Acontiostoma, and in describing S. capense I was of the same opinion. But further study b. ^^ c. £ Fig. 4. Stomacontion insigne, n.sp. a. Gnathopod 1 . b. Gnathopod 2. c. Maxilla 1 . d. Maxilla 2. e. Peraeopod 2. /. Peraeopod 3. g. Pleon segments 3-6 and uropods. h. Telson. of these forms is necessary. If the palp of maxilla 1 is of generic importance the 1st gnathopod might also be considered as such. Stomacontion insigne, n.sp. (Fig. 4). Occurrence: St. 160. Shag Rocks. 1 specimen about 6 mm. Description. Integument (as preserved) moderately indurated, smooth. Eyes absent. Side-plates deep, non-setose, 1st subtriangular but not markedly shorter than 2, 4 somewhat truncate below, 5 with posterior lobe deeper than anterior. Pleon seg- ment 3 remarkably shortened dorsally, forming a rounded hump, postero-lateral angle quadrate, slightly produced; segment 4 falling away abruptly from segment 3, with a strong upturned process on posterior margin. Telson oblong, slightly longer than broad, apex angularly and shallowly excised. Antenna 1 stout, 2nd and 3rd joints very short, flagellum 4-jointed, 1st joint longest, accessory flagellum2-jointed, 1st joint slender, longer than 1st joint of flagellum, 2nd joint minute. Antenna 2, 5th joint shorter than 4th, flagellum subequal to 5th joint, 4-jointed. 34 DISCOVERY REPORTS Mandible without molar, palp set far back. Maxilla i, inner lobe without setae, palp minute, i-jointed. Maxilla 2, both lobes slender, with 1-2 apical setae. Maxilliped, outer plate apically subacute, inner distal margin shallowly excised, 4th joint of palp quite rudimentary. Gnathopod 1, 6th joint shorter and narrower than 5th, ovate. Gnathopod 2, 6th joint distinctly shorter than 5th, only about two-thirds its length. Peraeopods 1-5 in general similar to those ofpepinii, but hind margin of 2nd joint of peraeopods 3-5 quite smooth; 5th joint abruptly narrower than the expanded 4th. Uropods 1 and 2 biramous, rami smooth. Uropod 3 consisting of a rather stout conical peduncle, without trace of rami. Genus Amaryllis, Hasw. Stebbing, 1906, p. 23 and p. 717 (Vijaya). Barnard, 1925, p. 324. Amaryllis macrophthalma, Hasw. Stebbing, 1888, p. 707, pi. xxix. Barnard, 1916, p. 114. Schellenberg, 1926, p. 243 (references); 1931, p. 10. Occurrence: 1. St. 51. Falkland Islands. 1 $ 12 mm., from kelp root. 2. St. 91. South Africa. 2 <$$, 2 $$ 10 mm., 4 immat. 6-7 mm. 3. St. 222. Cape Horn. 1 ? 13 mm. 4. St. WS 71. Falkland Islands. 1 ovig. $ 15 mm. 5. St. WS 85. Falkland Islands. 1 S 14 mm., 2 $$ 14-15 mm., 3 ovig. $? 14, 16 and 17 mm. Remarks. This appears to be the only occasion on which this species has been taken in this area since the 'Challenger' took a small specimen off Cape Virgins. The speci- mens do not differ in any respect except size from South African specimens. The <3 is not fully adult as the 2nd antennae are not longer than in the ?. The eyes are dark. The distribution is rather remarkable and it might perhaps be worth while to re- examine the East African specimen (Walker, 1909, p. 327) to see whether it is not really referable to the Cingalese species tenuipes. Distribution. Australasia; South and East Africa; Cape Virgins, 55 fathoms. Genus Cyphocaris, Boeck. Schellenberg, 1926, p. 243; 19266, p. 202. Schellenberg in the ' Valdivia ' Report has discussed the value of the specific characters of the species in this genus, and has shown that certain characters undergo considerable change during growth. C. richardi must certainly be regarded as the least specialized, followed by anonyx The prolongation of the 2nd joint of peraeopod 3 and the enlargement of the 6th joint of peraeopods 1-4 is a further development of a line of evolution already indicated in certain examples of richardi. The three species bouvieri, chaUengeri and faurei are closely related to one another, much more so than to richardi and anonyx. The transformation of the 2nd joint oi LYSIANASSIDAE 35 peraeopod 3 into a sharp spine containing glands, which are possibly poison glands, might almost be regarded as justifying generic distinction. Cyphocaris richardi, Chevr. Chilton, 1912, p. 464, pi. i, figs. 1-4 (anonyx, 11011 Boeck). Stephensen, 1915, p. 37, figs. 21, 22. Schellenberg, 1926, p. 245, fig. 4; 1926 b, p. 206, pi. v, fig. 1 and text-figs, za, 3, 4; 1929, p. 195 ; i93 x i P- 1 S- Occurrence: 1. St. 8. South Atlantic. 1 <$ 25 mm., 3 $$ 26-27 mm. 1 2. St. 71. South-west Atlantic. 1 S 27 mm., 2 ?? 30 mm., 31 immat. 16-21 mm. 3. St. 72. South-west Atlantic. 1 $ 31 mm. 4. St. 76. South-west Atlantic. 1 ovig. $ 31 mm. 5. St. 78. South Atlantic. 7 immat. 14-20 mm. 6. St. 81. South Atlantic. 1 immat. 21 mm. 7. St. 84. South-east Atlantic. 1 immat. 21 mm. 8. St. 86. South-east Atlantic 2 $$ 22 and 24 mm. 9. St. 89. South Africa. 2 immat. 20, 21 mm. 10. St. 101. South Africa. 4 3$ 23-25 mm., 8 $$ 25-30 mm. 11. St. 107. South-east Atlantic. 3 $$ 23-30 mm. 12. St. 114. Bouvet Island. 3 $$ 23-24 mm., 10 ?? 24-30 mm., 4 immat. 17-19 mm. 13. St. 197. South Shetlands. 1 ? 38 mm., 1 ovig. ? 40 mm. 14. St. 198. South Shetlands. 1 <$ 36 mm. 15. St. 239. South-west Atlantic. 4 S3 20-22 mm., 8 $$ 22-31 mm., 3 ovig. ?? 30-31 mm., 8 immat. 16-20 mm. 16. St. 253. South-east Atlantic. 7 immat. 14-21 mm. 17. St. 256. South-east Atlantic. 1 $ 20 mm., 1 $> 21 mm. Remarks. Notes 17, 18, 19, all referring to the specimens caught at St. 8, read as follows : " deep red, rostrum white with pale red tip ", " red, rostrum slightly paler red ", " orange-red, rostrum broken at tip, but whitish ". No. 2, 5 and 6 are recorded as being "bright orange", "bright orange-red" and "bright scarlet" respectively. All the present localities lie between about 32!° S and 52^ S, with two stations also in the South Shetlands. Chilton's record (as anonyx) is the most southerly (71 50' S) yet recorded. It is interesting to note that this species was not taken at any station on the homeward journey from Cape Town, i.e. in the Benguella Current along the west coast of Africa, in contrast with the other species recorded below. Ovigerous ?$ were taken in April (South Shetlands) and June (north-east of Falkland Islands). The largest ?? (no. 13) and the largest S (no. 14) both came from the higher latitudes. The least depth at which specimens were caught was 76 m. (no. 14) ; this was a night haul, but at the neighbouring station (no. 13) the species was not caught either by day or by night at lesser depths than 750-500 m. With this exception there is no evidence that the species ascends towards the surface at night. Distribution. Atlantic : 54 N-37 N and 14 S-55 S and nearly 72 S, 0-4900 m. Pacific. 1 All measurements in this genus are exclusive of the rostrum. 5-2 3 6 DISCOVERY REPORTS Cyphocaris anonyx, Boeck. Stebbing, 1888, p. 656, pi. xvi (tnicronyx). Chevreux, 1900, p. 165, pi. xiv, fig. 11 (coloured) (micronyx). Schellenberg, 1926, p. 244; 1926 b, p. 210, pi. v, fig. 2 and text-figs. 26, 5; 1929, p. 195. Pirlot, 19290, p. 5. Non Chilton, 1912, p. 464 (richardi). Occurrence: 1. St. 78. South Atlantic. 2 ?$ 13 mm. 2. St. 81. South Atlantic. 3 $$ 12-13 mm. 3. St. 87. South-east Atlantic. 3 S3 10-12 mm., 3 ?$ 12-13 mm., 1 immat. 8 mm. 4. St. 89. South Africa. 4 ?°. 10-13 mm - 5. St. 253. South-east Atlantic. 1 ? 13 mm. 6. St. 256. South-east Atlantic. 2 ?? (1 ovig.) 13-14 mm., 2 juv. 8-9 mm. 7. St. 281. South Atlantic. 3 $°. 12-13 mm. 8. St. 287. Mid-Atlantic. 3 $$ 9-12 mm. 9. St. 295. Mid- Atlantic. 1 $ 13 mm. Remarks. No. 2 is recorded as being "bright scarlet". The present collection fills gaps in, but does not materially extend, the known distribution of this species. Distribution. Atlantic: 78 N-35J S, 310-3000 m. Indo-Pacific. Cyphocaris challenged, Stebb. Stebbing, 1888, p. 661, pi. xvii. Chevreux, 1905 {Bull. Inst, ocean. Monaco, no. 27), p. 1, figs. 1, 2 (alicei). Schellenberg, 1926, p. 243 ; 1926 b, p. 212, pi. v, fig. 3 and text-figs. 2 d, 6-10; 1929, p. 195. Pirlot, 1929 a, p. 7. Occurrence: 1. St. 78. South Atlantic. 1 $ 11 mm., 1 juv. 7 mm. 2. St. 83. South-east Atlantic. 1 <$ 11 mm. 3. St. 87. South-east Atlantic. 6 $$ 8-5-10 mm., 10 $? 6-9 mm. (2 ovig.). 4. St. 89. South Africa. 2 <$ 1 immat. 13 mm (St. 281.) 4. St. 287. Mid-Atlantic. 2 immat. 10-nmm. 5. St. 296. Mid-Atlantic. 1 immat. 11 mm. Remarks. The large ? (no. 3) seems to be the first known specimen which is ap- proximately mature. The brood lamellae are elongate linguiform, with setose margins. It is also remarkable in that both mandibles retain a 2-jointed rudiment of the palp. The ventral surface in the smaller specimens is more or less bulging, a fact which may indicate parasitic (blood-sucking) habits. The known distribution in the Atlantic is much extended by the above finds, viz. to south of the equator (2 49' S) in the Gulf of Guinea, and to 35 S Mid- Atlantic. Distribution. Atlantic: 64 N-47 N, 1800-2800 m. Genus Paralysianopsis, Schell. Schellenberg, 193 1, p. 7. Barnard, 193 1, p. 425 (Ausfronisimus). Side-plate 1 not expanded below, 5 evenly bilobed. Pleon segment 3 with postero- inferior angle produced, rounded. Telson short, ovate, with a short terminal notch. Antenna 1 stout, 2nd and 3rd joints very short. Epistome straight, not prominent ; upper lip produced in an acute process. Mandible with molar moderate, palp attached over molar. Maxilla 1 , outer lobe with 7-8 spines, palp moderately slender. Maxilla 2, lobes 38 DISCOVERY REPORTS moderately slender, subequal in length. Maxilliped, outer plate with smooth inner margin. Gnathopod i feebly subchelate. Uropod 2 with inner ramus constricted. Uropod 3, 2nd joint of outer ramus two-thirds length of 1st. Branchiae simple, apparently without accessory branchiae. Remarks. A genus which has many of the characters of Onisimus, but which differs in the subequal and more slender lobes of maxilla 2, and the large 2nd joint of the outer ramus of uropod 3. In both of these characters it resembles Lysianella, but lacks the enlarged 4th joint of antenna 2 found in that genus. The produced upper lip is com- parable with that of Lysianella. From Paronesimns it is distinguished by the 2nd maxilla. The epistome and upper lip for this latter genus are not described, unless we can assume from Stebbing's words (1894, Bijdr. Dierk., xvn, p. 14) : " The single specimen was dissected under the impression that it belonged to Chironesimus debruynii. . . ", that the upper lip was strongly projecting as in that species. Further distinguished from Pseiidonesimns, Chevr. 1926 by the feebly subchelate 1st gnathopod and the 3rd uropod. The other genus to which this form might be run down in Stebbing's key (1906) is Paratryphosites, but the epistome and upper lip are not described, at least not in the works accessible to me. Paralysianopsis odhneri, Schell. (Fig. 6). Schellenberg, 193 1, p. 7, fig. 2. Barnard, 193 1, p. 425 (A. rhinoceros). Occurrence : St. WS 25. South Georgia. 1 $ 6 mm. Description. Integument (as preserved) not indurated. Head with anterolateral angle quadrate. Eyes oval, dark. Side-plate 1 parallel-sided, somewhat rounded below; 5 evenly bilobed. Postero-inferior angles of pleon segments 1 and 2 quadrate, of seg- ment 3 produced in a rounded lobe. Pleon segment 4 dorsally depressed behind the Fig. 6. Paralysianopsis odhneri, Schell. a. Gnathopod 1. b. Peraeopod 3. c. Pleon segments 3-6. d. Telson. e. Uropod 3 /. Profile of epistome and upper lip. LYSIANASSIDAE 39 proximal hump, but not carinate. Telson short, oval, with a short apical notch, an apical spinule on each lobe. Antenna 1, flagellum 9-jointed, accessory flagellum 5-jointed. Antenna 2, flagellum 8 -jointed. Epistome straight, upper lip produced in an acute, slightly upturned, process. Mandible, molar moderately strong, palp attached above molar or above its posterior margin, but not behind it. Maxilla 1, outer lobe with 7-8 serrulate spines, palp ex- tending beyond apex of outer lobe, moderately slender, apex with four short stout spinules and a seta. Maxilla 2, both lobes nearly equal in length and moderately slender. Maxilliped, inner plate with two apical short spinules, outer plate with smooth margin. Gnathopod 1, 6th joint nearly as long as (upper margin) 5th, slightly tapering, palm short, oblique, defined by a rather long slender spine and a seta. Gnathopod 2, 6th joint half length of 5th, narrow ovate, minutely subchelate. Peraeopods 1-5 slender, 2nd joint in peraeopods 3-5 ovately expanded, longer than wide, hind margin serrulate, 4th joint moderately expanded in peraeopod 3, but less so in peraeopods 4 and 5. Uropod 2, rami slender acuminate, inner ramus constricted. Uropod 3 rather stout, rami a little longer than peduncle, outer ramus slightly longer than inner, its 2nd joint two-thirds length of its 1st joint. Distribution. Falkland Islands. Genus Lysianassa, M. Edw. Stebbing, 1906, pp. 37, 718. Lysianassa variegata (Stmpsn.). Stebbing, 1888, p. 682, pi. xxiii and 1910 a, p. 449. Occurrence:!. St. 90. South Africa. 2 ?? 9-10 mm. 2. St. 91. South Africa. 2 $$ (1 ovig.) 7-5 mm. Distribution. South Africa (False Bay to East London). Lysianassa falklandica, n.sp. (Fig. 7). Occurrence: 1. St. WS 85. Falkland Islands. 1 $ 7 mm. Type. 2. St. WS 97. Between Falkland Islands and South America. 2 ovig. $$ 9 mm., 1 immat. 6-5 mm. Description. Integument indurated. Head, peraeon and pleon dorsally with minute scattered setules. Head with antero-lateral angle quadrate or subacute. Eyes rather narrow oval-reniform, brown. Side-plates 1-4 deep, 1 slightly expanded forwards, 4 not strongly excavate, the excavation evenly rounded. Pleon segment 4 with dorsal profile slightly excavate in middle; postero-inferior angles of segment 1 rounded, of 2 quadrate, of 3 produced backwards in a rounded lobe. Telson longer than wide, distal margin truncate or feebly excised, a spinule on each apex. 4° DISCOVERY REPORTS Antenna i, flagellum 7-jointed, accessory flagellum 3 -jointed. Antenna 2, flagellum 9-jointed. Epistome not prominent, separated by a deep groove from the upper lip which is produced in a linguiform process. Mouth-parts as in plumosa (Sars, 1895, pi. xvi, fig. 1 , as costae), but inner lobe of maxilla 2 scarcely broader than outer lobe. Gnathopod 1, 2nd joint stout, straight, 5th oblong, 6th longer than 5th, narrow, tapering. Gnathopod 2, 6th joint rather more than half length of 5th, feebly chelate. Peraeopod 3, 2nd joint strongly expanded, subcircular, hind margin feebly notched. Peraeopod 4, 2nd joint ovoid, longer than wide, hind margin distally emarginate. Peraeopod 5, 2nd joint broadly ovate, nearly subcircular. Fig. 7. Lysianassafalklandica, n.sp. a. Gnathopod 1. b. Gnathopod 2. c. Side-plate 4. d. Telson. e. Profile of epistome and upper lip. /. Pleon segment 3. g. 2nd joint of peraeopod 3. h. 2nd joint of peraeopod 4. i. 2nd joint of peraeopod 5. j. Uropod 2. k. Uropod 3. Uropod 2, inner ramus constricted. Uropod 3 not very short, the rami not rudi- mentary or reduced, upper outer margin of peduncle distally lobed, with 1-2 spinules on its upper margin. Branchiae tending to be slightly folded. Accessory branchiae absent. Remarks. It is perhaps possible that this species may prove to be the same as Dana's tiasnta from Rio de Janeiro, which Stebbing (1906) regards as a doubtful or inadequately described species. Bate's description (1862, p. 66), quoted from Dana, gives no criteria for comparison; his figure (pi. x, fig. 6), which is shaded and therefore taken from an actual specimen, shows the postero-inferior angle of pleon segment 3 much less pro- duced than in the present species. The 1st antenna is described and figured as longer than the 2nd antenna, which is not so in the present specimens. LYSIANASSIDAE 4I Genus Socarnoides, Stebb. Stebbing, 1888, p. 690 and 1906, p. 47. See also Schellenberg, 193 1, pp. 6, 22. Although there are no representatives of this genus in the ' Discovery ' collection, I make no apology for introducing the following discussion on these Antarctic or sub- Antarctic forms. (But see also under Acidostomella cnltrifera, supra p. 32). The type species is kergueleni, Stebb. 1888. In 1888 Stebbing, with one of S. I. Smith's specimens of " Lysianassa" kidderi before him, pointed out the differences between it and Socarnoides kergueleni, and in 1906 assigned the former to the genus Nannonyx, Sars 1891. In 1909 Chilton united S. kergueleni, Ephippiphora kroyeri, White, N. thomsoni, Stebb., and L. stebbingi, Thorns., with kidderi, Smith, but under the later generic name Nannonyx. Stebbing then referred (1910, p. 571) N. thomsoni to a new genus Parazvaldeckia, which agreed with Waldeckia in possessing accessory branchiae. In 1922 Tattersall accepted Chilton's synonymy and Stebbing's genus Parazvaldeckia, and expressed the hope that this form, described under at least half a dozen specific names and referred to three genera, had at last come to rest. But if all these "species " are really synonymous, he defeated his own object by adopting the oldest specific name and the latest generic name. Monod (1926) adopted Nannonyx, and Stephensen (1927) followed Tattersall. The name should be Socarnoides kidderi (Smith). But it appears to me to be very doubtful whether all these forms are legitimately united. In 1921 Chilton (1921 a, p. 35) was able to distinguish two of the forms he had previously united : a form which he refers to Ephippiphora kroyeri (using the preoccupied generic name) and another which he refers to Nannonyx kidderi, with Parazvaldeckia thomsoni as a synonym. I feel sure that our knowledge of these forms is still inadequate, in spite of Chilton's words (1909, p. 617) that "this species has already been fully de- scribed by various other authors ". Some points of conflict in these descriptions may be discussed. The accessory branchiae were first mentioned by Stebbing (19 10) and led to the in- stitution of the genus Parazvaldeckia "from its agreement with Waldeckia in possessing accessory lobes to the branchial vesicles". Presumably they are present on segments 2-6, but neither Stebbing nor Stephensen (1927, p. 301) state the actual number. It is not fair to assume that Stebbing overlooked them in describing S. kergueleni. Nor are they mentioned by Sars in the description of Nannonyx gdesii. We may therefore separate a form Parazvaldeckia thomsoni (Stebb.), New Zealand, which is further characterized by having the postero-inferior angle of pleon segment 3 "acutely up- turned" (Stebbing, 1906, p. 36). The 3rd uropod is very short with the inner ramus almost rudimentary, as in Nannonyx. But the character of the epistome and upper lip is unknown. 42 DISCOVERY REPORTS The epistome and upper lip are not at all prominent in N.goesii or in the form figured by Monod (1926, fig. 50). But in Socamoides they are both prominent, the epistome forming a very conspicuous plate. Stephensen's fig. 2 (1927) shows a strongly projecting profile very similar to that of the upper lip in kergueleni, though the description says the epistome projects. What was the character of the epistome and upper lip in Chilton's (1909 and 1921^) and Tattersall's specimens? A further point arises in the comparison of the shape of the 4th side-plate. Monod figures a very deep excavation, the lobe extending backwards to the end of the 5th side-plate. Thomson (1892, Proc. Roy. Soc. Tasman., p. 64, pi. v, fig. 10) and Tattersall figure a rectangular excavation. Both forms are utterly different from Stebbing's figure of kergueleni, and surely the agreement between Thomson's and Tattersall's figures is not accidental, but expresses a real difference which should cause one to hesitate before uniting these forms with kergueleni. Is the Parawaldeckia kidderi of Tattersall (which has accessory branchiae) a synonym of " Lysianax'" stebbingi, Thorns.? A comparison of the figures of the 1st gnathopod (and to a less extent the 2nd gnathopod) given by Stebbing (1888), Thomson (1892), Tattersall (1922), Monod (1926), and Stephensen (1927) leads one also to the conclusion that several (two at least) species have been unjustifiably united. This criticism may sound drastic, but it shows that the union of all these forms under the one name kidderi is most unfortunate. One must admit that Stebbing's description of kergueleni is a full and satisfactory description ; Stephensen's specimens are easily recognizable, as are Monod's and probably also Tattersall's. Though Stephensen com- pares and contrasts his specimens with kergueleni, one would have liked a figure of the 4th side-plate ; and in the case of the 'Belgica' specimens one would like to know whether accessory branchiae were present. One may perhaps hazard a guess that the 'Belgica' specimens will prove to be a species of true Nannonyx; that P. kidderi, Tattersall will be synonymous with stebbingi, Thorns, and a true Parazvaldeckia, but distinct from thomsoni, Stebb. As for Stephensen's specimens they have the upper lip of Socamoides, the 3rd uropod of Nannonyx, plus the accessory branchiae of Parazvaldeckia. A thorough study of abundant Australasian material is obviously required. Finally, although Stebbing compared his genus with Socarnes, Boeck, the comparison might have been made with Lysianassa which is closely allied with Socarnes. The dis- tinctive features of Socamoides, which separate it from both the other genera, are the maxillipeds and the prominent epistome, and in both of these features it shows an approach to Socarnopsis, Chevr., 1910. These remarks were written before the appearance of Schellenberg's 1931 paper. LYSIANASSIDAE 43 Genus Waldeckia, Chevr. Chevreux, 1906, p. 13. Waldeckia obesa (Chevr.). Chevreux, 1906, p. 15, figs. 8-10 and 191 1, p. 403. Chilton, 1912, p. 471. (zschauii, non Anonyx zschauii, Pfr.) Barnard, 1930, p. 323, fig. ici (references). Occurrence: 1. St. 170. South Shetlands. 1 $ 25 mm., 2 juv. 11 mm. 2. St. 172 3. St. 184 4. St. 189 5- St. 195 South Shetlands. 1 o 20 mm., 1 ovig. $ 25 mm. Palmer Archipelago. 1 $ 18 mm., 1 $ 25 mm. Palmer Archipelago. 2 SS 18 and 22 mm., 6 $$ 21-22 mm. (2 ovig.). South Shetlands. 1 J 1 18 mm., 1 $ 15 mm. Remarks. The postero-inferior angle of pleon segment 2 is quadrate with a small upturned point, as Schellenberg remarks ; and the antero-inferior angle of pleon segment 1 is also quadrate. The bathymetrical range is rather noteworthy, being from 36 m. (no. 3) to 425 m. (no. 2). Distribution. Coats Land; Palmer Archipelago and Graham Land; McMurdo Sound; 'Gauss' winter station; South Sandwich Group. Genus Aristias, Boeck. Stebbing, 1906, pp. 49, 718. As regards the Antarctic species, Walker described neither the epistome nor the upper lip, and Schellenberg only described the former. A certain amount of doubt therefore arises as to the identity of the specimens listed below. Aristias antarcticus, Wlkr. (Fig. 8 a, b). Walker, 1907, p. 11, pi. iii, fig. 5. Barnard, 1930, p. 324. Non Schellenberg, 1926, p. 255, fig. 10 {antarcticus non Wlkr. = ? sp.nov.). Occurrence: 1. St. 42. South Georgia. 1 $ 12 mm. 2. St. 45. South Georgia. 1 ovig. $ 12 mm. 3. St. 149. South Georgia. 3 ?? 8, 9 and 11 mm. 4. St. 170. South Shetlands. 1^7 mm., 1 $ 8-5 mm. 5. St. MS 71. South Georgia. 2 <$S 9 mm., 6 ?$ 10-12 mm. Remarks. These specimens are referred to Walker's species solely on their agreement with his figure of the dorsal profile of pleon segment 4. Future research must show whether they agree with his type specimen as regards the epistome and upper lip. The upper angle of the upper lip is always quadrate, but varies a little in the extent to which it protrudes beyond the epistome. The telson has the lobes more tapering than in Walker's figure, but not angularly bevelled off as figured by Schellenberg. Peraeopods 1-5 have the 5th joint markedly wider than the 6th, as in Walker's figure. Uropod 3 in the ovigerous ? has both rami broadly ovate, much broader than in Walker's figure or 6-2 44 DISCOVERY REPORTS Sars' figure of tumidus (1895, pi. xviii, fig. 1), the margins strongly serrulate except the outer margin of the outer ramus which is smooth. The specimens from St. 170 have the antero-lateral angle of the head more like Schellenberg's fig. 10 a than Walker's; perhaps the blunter angle is characteristic of younger specimens. Schellenberg himself remarked on the differences between the 'Gauss' and the 'Discovery' (1901-04) specimens. Distribution. McMurdo Sound. Aristias collinus, n.sp. (Fig. 8 c, d). Occurrence: 1. St. 170. South Shetlands. 1 immat. (?) 9 mm. Type. 2. St. 175. South Shetlands. 1 juv. 7 mm. Description. Distinguished at once from antarcticus by the rounded upper lip, and the much deeper dorsal depression on pleon segment 4, which is followed by a rounded hump or boss (not a carina). Telson with the lobes angularly bevelled off distally as in Schellenberg's fig. 10 b (feebly so in no. 2, but distinctly so in no. 1). c. Fig. 8. Aristias antarcticus, Wlkr. a. Pleon segments 3-6. b. Profile of epistome and upper lip. Aristias collinus, n.sp. c. Pleon segments 3-6. d. Profile of epistome and upper lip. Remarks. I fully expect that, though this species resembles the 'Gauss' specimens from Kerguelen (referred by Schellenberg to antarcticus), the latter will be found to be distinct if the upper lip be closely examined. Ambasiopsis, Brnrd. Barnard, 1931, p. 425. Agreeing with Metambasia, Steph. 1923, but differing as follows : 1st gnathopod feebly subchelate, outer plate of maxilliped non-spinose, inner ramus of uropod 2 not con- stricted, peraeopods 3-5, especially 5, much shorter and 4th joint more expanded, 3rd joint of antenna 2 not expanded. The last character is provisional as the only $ (see uncinata, infra) may not have attained its adult characters. Ambasiopsis georgiensis, Brnrd. (Fig. 9). Barnard, 1931, p. 425. Occurrence: St. 159. South Georgia. 3 ovig. ?? 10-11 mm. Description. Integument indurated. Head with antero-lateral angle pointed. Eyes not visible. Peraeon dorsally rounded. Side-plate 1 subtriangular, pointed below, the LYSIANASSIDAE 45 lower corner concealed by side-plate 2. Side-plates 2-4 deep but not closely packed, 4 with moderately deep excavation; 5 notched, the two lobes subequal; 6 similar but posterior lobe broader, though not deeper, than anterior; 7 trapezoidal, the hind margin longer than the anterior. Pleon rounded, except for the rather high carina on segment 4, which slopes gradually on the anterior side and falls abruptly and vertically on the posterior side, very much as in Ambasia atlantica. Postero-inferior angles of segments 1 and 2 rounded, of 3 rather less than a right angle, the corner rounded. Telson not twice as long as wide, cleft for three-quarters of its length, lobes slightly dehiscent, apically acute with a subapical spinule on outer side, and two lateral marginal spinules. Fig. 9. Ambasiopsis georgiensis, Brnrd. a. Side-plates 1 and 2 and gnathopod I, with palm further enlarged. b. Gnathopod 2, with palm further enlarged, c. Profile of epistome and upper lip. d. Pleon segments 3 and 4. e. Telson. /. Side-plates 4 and 5 and peraeopod 3. Antenna 1, peduncle stout, 1st joint apically produced on upper margin, 2nd and 3rd joints very short, flagellum 8-jointed, 1st joint half as long as 1st peduncular joint, setose, accessory flagellum 3-jointed, 1st joint the longest, but not as long as 1st flagellar joint. Antenna 2, 4th joint longest, 5th shorter than 3rd, flagellum shorter than peduncle, 9-jointed. Epistome not projecting, upper lip produced in a rounded lobe. Mandible, cutting edge straight with a denticle at each end, spine row minute, molar strong, truncate, setose, palp longer than trunk, inserted over molar, 3rd joint two-thirds length of 2nd. Maxilla 1, inner lobe short, ovate, tipped with two long and one short setae, outer lobe with seven feebly serrate spines, palp extending beyond outer lobe, narrow, tipped with two short stout spines and 1-2 setules. Maxilla 2, inner lobe distinctly shorter than outer, as in faeroens is. Maxilliped, inner plate with 3-4 apical spinules, outer plate with minutely serrate inner and distal margin but without spinule, palp rather stout. 4 6 DISCOVERY REPORTS Gnathopod i feebly subchelate, 6th/ joint shorter than 5th, oblong, upper margin slightly indented, lower margin spinose, passing into the short, oblique and minutely fimbriate palm by a rounded angle, finger short, stout, curved. Gnathopod 2, 6th joint oval, half length of 5th, with a short straight almost transverse palm, with one short spinule at the angle. Peraeopod 3, 2nd joint broadly ovate, hind margin very obscurely notched, anterior margin spinulose distally, 4th joint moderately expanded, 3rd-6th joints very feebly armed with a few spinules and setules. Peraeopod 4, 2nd joint less broadly ovate, other- wise like peraeopod 3. Peraeopod 5, 2nd joint more broadly expanded than in peraeopod 4, but more oblong than in peraeopod 3, longer than the other joints together, 4th joint less expanded than in peraeopods 3 and 4, 3rd-6th joints rather more strongly armed with spinules. Uropods 1 and 2 extending very slightly beyond apex of uropod 3 , rami shorter than peduncles, acuminate, spinose, inner ramus of uropod 2 not constricted. Uropod 3, rami longer than peduncle, 2nd joint of outer ramus well developed, inner ramus ex- tending to middle of 2nd joint of outer, both rami without spines or setae. Ambasiopsis uncinata, n.sp. (Fig. 10). Occurrence: St. 170. South Shetlands. 1 $ 10 mm., 1 juv. 6 mm. Remarks. The two forms here placed under kergueleni should in my opinion be regarded as specifically distinct. The raised keel on pleon segment 4 is correlated with a more prominently projecting upper lip. b. Fig. 13. Tryphosa kergueleni (Miers). Dorsal profile of pleon segment 4 and profile of epistome and upper lip of: a. typical form; b. hypsilophic form. Schellenberg figures the two forms of carina, but says nothing about the upper lip. Both forms were found together at the ' Gauss ' winter station. In the Discovery collec- tion the hypsilophic form was found in a different locality and in much deeper water. The two forms should be distinguished in all future records, and earlier records should be re-examined. Distribution (kergueleni sensu lato). Kerguelen; ' Gauss' winter station; Ross Sea; South Georgia; New Zealand. Tryphosa major, n.sp. (Fig. 14). Occurrence: 1. St. 159. South Georgia. 4 $$ 16-21 mm., 3 ovig. $$ 18-22 mm. 2. St. 170. South Shetlands. 2 S3 14 mm., 1 ? 14 mm., 1 ovig. $ about 20 mm. (mutilated). Types. 3. St. 175. South Shetlands. 3 $$ 12, 13, 16 mm. Description. Closely resembling the typical form of kergueleni in pleon seg- ments 3 and 4, but apparently a larger species. In other respects generally re- sembling kergueleni but inner lobe of maxilla 1 with six plumose spine setae, and epistome produced in a convex, but somewhat flattened lamina from between -"""^ a. 6. the bases of the 2nd antennae to the pig. 14. Tryphosa major, n.sp. a. Pleon segments 3 upper lip. and 4. b. Profile of epistome and upper lip. LYSIANASSIDAE SI Tryphosa adarei, Wlkr. (Fig. 15). Walker, 1903, p. 49, pi. viii, figs. 38-44. Barnard, 1930, p. 326. Occurrence: St. 175. South Shetlands. 2 S epistome and The telson and absence of Strong upstanding upper lip. b. Pleon segments 3-6 and telson. spines on the outer plate of the maxilliped c - Telson. distinguishes this species from miersi Stebb. All the specimens are pale creamy in colour, and there is no trace of eyes. Tmetonyx carinata (Schell.) Schellenberg, 1926, p. 271, fig. 18 (Tryphosa c). Occurrence: St. 170. South Shetlands. 1 (J 16 mm. Remarks. The triangular process on the upper lip, the character of the 1st gnathopod (simple in $, feebly subchelate in $, and with a strong tooth on inner margin of finger), and the 2nd maxilla seem to indicate that this species would be better placed in the present genus. It should be compared with the type of T. stebbingi (Wlkr.), the upper lip of which is undescribed. Distribution. 'Gauss' winter station, 385 m. Genus Katius, Chevr. Chevreux, 1905 {Bull. Inst, ocean. Monaco, no. 35), p. 1. Stebbing, 1906, pp. xxi, 721. Schellenberg, 1927, p. 681. This genus was originally placed near Orchomenopsis and occupies a similar position in the works of Stebbing, Stephensen (1925) and Schellenberg. It seems remarkable that no one has commented upon its extraordinary resemblance to Eurythenes. In face of the acceptance of the genus by all authorities it may seem bold to ask what are the characters on which Katius is separated from Eurythenes and to question the validity of these characters for generic purposes. A comparison of the descriptions and figures given by Chevreux, Sars (1895, p. 85, pi. xxx) and Schellenberg (1927) shows the following differences: Katius has a less s6 DISCOVERY REPORTS prominent epistome, two setae on the inner lobe of maxilla i instead of several, shallower side-plates, especially side-plate 2, the hind lobe of side-plate 5 deeper than the anterior lobe instead of vice versa, and elongate dactyli on peraeopods 1-5. The first two of these characters can be excluded from the discussion in view of the remarks made below on the Discovery specimens. On the other hand, there is such an obvious agreement in the mouth-parts and other appendages (v. infra) that the differences just mentioned would seem to be specific rather than generic, with the exception perhaps of the dactyli. The enlargement of the dactyli probably indicates a mode of life different from that of Eurythenes gryllus (cf . Stephensen, 1915, pp. 37 and 43, and Schellenberg, 1926 b, p. 241). I would suggest that this mode of life (in Katias) is predaceous on quickly moving animals, rather than semi-parasitic, because the mouth-parts show no trace of degeneration as they do in e.g. Chevreuxiella, Steph. If enlarged dactyli be regarded as a generic feature, are Liljeborgia macronyx, Epimeriella macronyx, Hyperia macronyx also to have new generic names created for them? The difference in length of the dactyli in the allied species of these genera may not be as great as that between Katius and Eurythenes ; but that very fact weakens the value of the character for generic purposes. The physiological argument was used in the Terra Nova Report (1930, p. 346) for splitting up the Iphimediids, but in that case the separation of the genera was made on the mouth-parts, which are not only more important physiologically, but showed far greater morphological differences than the mere difference in the length of the dactyli in Katius and Eurythenes. In the present family a great importance— possibly too great an importance — has been attached to the characters of the mouth-parts. Where the characters of the mouth-parts are identical, as in Eurythenes and Katius (even as regards the character of the spines on the outer lobe of maxilla 1 , and the warts along the inner margin of the outer plate of the maxilliped) there would seem to be no question of generic separation on morphological grounds. The branchiae are said to be simple in Eurythenes, in Katius they are slightly pleated. Yet it must be admitted that Katius has the head curved downwards (cf. Stephensen, 1925, p. 126) and a somewhat inflated and arched peraeon which gives it an appearance not unlike that of a Lanceolid. Katius obesus, Chevr. (Fig. 21 and PI. I, fig. 1). Chevreux, 1905 {he. cit.), p. 1, figs. 1-3. Stephensen, 1915, p. 37; 1925, p. 126. Shoemaker, 1920 (Canad. Arct. Exp.), p. 8. Schellenberg, 1927, p. 681, fig. 72; 1931, p. 16. Occurrence: 1. St. 78. South Atlantic. 1 juv. 16 mm. 2. St. 101. South Africa. 1 ovig. 942 mm. 3. St. 107. South-east Atlantic. 1 juv. 16 mm., 1 ^ 25 mm. 4. St. 253. South-east Atlantic. 1 juv. 23 mm. (no penes, no brood lamellae). 5. St. 288. Mid-Atlantic. 1 juv. 23 mm. (no penes, no brood lamellae). LYSIANASSIDAE 57 Remarks. Antero-lateral angle of head rounded (but not so blunt as in Chevreux's figure) in the young, becoming subacute in the <$ and half-grown specimens, and acute in the large $. A medio-dorsal keel from peraeon segment 4 to pleon segment 4, stronger posteriorly, and more prominent in adult than young specimens. If the pleon be flexed a basal depression is visible on segments 2-4. The 6th pleon segment bears two dorso-lateral low keels which project as triangular lobes on either side of the base of the telson (cf. Liljeborg, he. cit., quoted under Eurythenes, infra, p. 7). Antero-inferior angle of pleon segment 1 in young rounded, in adult quadrate; postero-inf erior angle of segment 2 with a small point ; inferior margin of pleon segment 3 convex in young, nearly straight in adult $. The antero-inferior angle and margin is feebly costate, and on segments 1 and 2 there is a feeble oblique keel. The epistome is considerably more prominent than described by Chevreux, and in fact does not differ essentially from that of Eurythenes gryllus (Sars, 1895, pi. xxx). Fig. 21. Katius obesus, Chevr. a. Pleurae of pleon segments 1-3, adult ? (St. 101). b. The same, juvenile (St. 78). c. Spine from apex of outer lobe of maxilla 1. d. Apex of outer plate of maxilliped. e. Anterior margin of head with basal joints of antenna 2, epistome and upper lip. Basal joint of antenna 2 large, bulbous, visible externally (as in Eurythenes). Maxilla 1, outer lobe with spines which bear acute and rather widely spaced denticles (as in Eurythenes), inner lobe with 2-4 plumose setae in young, five in adult. Maxilliped, outer plate with minute wart-like spinules on inner margin (as described by Schellen- berg for Eurythenes, 1927, p. 678), 2-3 more obviously spiniform ones distally, and 2-3 plumose setae on outer distal margin. Branchiae with moderate folds, seemingly indicated in Chevreux's fig. 3 C, but not mentioned in his text. Arising from near the base of each branchia on segments 2-7 posteriorly and externally is a small irregularly triangular accessory lobe. After the above remarks there would seem to be no need to harp further on the similarity of Katius to Eurythenes. Besides the dactyli of peraeopods 1-5 and the side- plates, a further difference may exist in the branchiae, but Liljeborg 's statement (loc. cit. under Eurythenes, p. 6) ought to be confirmed. 5 8 DISCOVERY REPORTS The ovigerous $ (St. 101) seems to be the largest and the only adult specimen yet captured. The 'IngolP took a specimen about 33 mm. in length with small brood lamellae. A coloured sketch of this large $ was taken at the time and is here reproduced. The colour of no. 1 was noted as "white with pale brown eyes; hepatic and other internal organs visible as a grey mass". The occurrence of this species in the Southern Atlantic has not hitherto been recorded, except by Schellenberg, 193 1. Distribution. North Atlantic: Davis Strait to Azores (about 65 N-36 N) ; North Pacific, 0-3000 m. Genus Eurythenes, S. I. Smith. Liljeborg, 1865 (N. Act. Soc. Upsala, ser. 3, vi, p. 11 ; or Arsskr. Kong. Univ., p. 6) (Eurytenes, preocc). Sars, 1895, p. 85 (Euryporeia). Chevreux, 1900, p. 24 (Euryporeia). Stebbing, 1906, p. 72 (references). Schellenberg, 1927, p. 678. As Chevreux remarks, Smith in changing the preoccupied Eurytenes into Eurythenes altered the spelling though not the sound in languages where " h " is silent. Relaxation of the nomenclatorial rules in favour of Sars' name would set a precedent which might have far-reaching consequences in these days of linguistic aspirations. The following discussion centres around the magnificent Amphipod collected by d'Orbigny in the stomach of a fish caught near Cape Horn and described by M. Edwards as Lysianassa magellanica. Liljeborg (loc. cit.) on receiving three large Amphipods taken from the stomach of Scymnus borealis at Hammerfest, came to the conclusion that they were identical with the Antarctic form, and gave a description of them under the name Eurytenes magellanicus . The Arctic form, however, had already been described in 1822, and is now known as Eurythenes gryllus (Licht.). In 1865 Bate (Zool. Rec., 11, p. 331) criticized Liljeborg's opinion as to the identity of the Arctic and Antarctic forms, pointed out several differences, and maintained the accuracy of his description and figure of magellanicus in the British Museum Catalogue (1862, p. 66, pi. x, fig. 5). No great significance attaches to the differences mentioned by Bate, though we may note that the depth of the peraeon is one character which distinguishes Eurythenes from Katius (cf. supra). But Bate himself seems to have fallen into an error, for he uses the words (loc. cit., 1865, p. 332) "Lysianassa magellanica, With, its squamiform, undivided telson. . . ", and adduces this as the final argument why magellanica cannot be put into the genus " Anonyx" from which he says he cannot distinguish Liljeborg's genus Eurytenes. He claims (1865, p. 331) to have seen the type specimen and from it to have made small corrections in the figure given in 1862. Yet M. Edwards in his original description distinctly states "deux appendices styliformes. . . representent le septieme anneau" (cf. infra). LYSIANASSIDAE 59 I think we may safely rely on M. Edwards' statement, and the conclusion is not too hazardous that magellanica is a Enrythenes. But the validity of the species must be tested by a comparison of the type, if extant, with actual specimens of gryllns. I am indebted to Prof. Gravier of the Paris Museum for the information that, though there is a specimen of Lysianassa magellanica in poor condition in the Paris Museum, he very much doubts whether it is the type specimen studied by M. Edwards. As regards gryllus, the descriptions are not too clear on all points. Stebbing's diagnosis (1906) includes the contradictory statements of Sars and Liljeborg, and also a further statement about certain segments of the peraeon and pleon. Schellenberg (1927, p. 679) has introduced a further complication by stating that the last peraeon segment and the five following (pleon) segments have a low longitudinal groove (Rinne). Obviously one and the same segment cannot be both dorsally rounded and keeled, or both grooved and keeled. Eurythenes gryllus is worthy of a fuller description based on as much material as possible ; there are already quite a number of specimens in European Museums (Stephensen, 1925, p. no). One difference in the published figures may be noted here. Liljeborg (loc. cit., figs. 1 and 22) shows the 2nd pleon segment with the postero-inferior angle produced as a distinct point, from which arises an oblique keel. Sars (1895, pi. xxx) shows scarcely any point on the broadly rounded postero-inferior angle. Though the Magellanic species must remain for the present sub judice, it may be useful to quote here M. Edwards' original description. Eurythenes magellanicus (M. Edw.). M. Edwards, 1848 (Ann. Sci. Nat. Hist., ser. 3, zool. ix), p. 398. Lucas, 1857 (Anim. nouv. Austr. I'Amer. dn Slid. Entomol.), p. 13, pi. i, fig. 3. Bate, 1862, p. 66, pi. x, fig. 5 (traced from Lucas' figure and corrected from the type specimen). ? non Liljeborg, loc. cit. supra. "L'ordre des Crustaces amphipodes n'est represente jusqu'ici dans nos collections que par des animaux de tres petite taille, tels que les Orchesties, les Talitres et les Crevettes de nos cotes ; mais il existe dans l'ocean Antarctique une espece de Lysianasse qui est presque aussi grande que les Ecrevisses ordinaires de nos rivieres. Cet Amphipode remarquable a ete trouve par M. d'Orbigny dans l'estomac d'un Poisson peche pres du Cap Horn, et fait partie des collections deposees par ce voyageur dans notre Museum national. La forme generale de ce Crustace est trapue ; la tete petite, et garnie en avant de lobes jugaux qui s'avancent entre la base des antennes superieures et inferieures. Les antennes de la seconde paire sont greles, sans poils ni cupules, et atteignent le quatrieme anneau du thorax lorsqu'elles sont reployees en arriere. Les pattes anterieures sont tres courtes; celles de la deuxieme paire sont longues, tres greles, et terminees par une petite griffe pointue. Les pattes des trois dernieres paires sont tres petites et subdenticulees sur les bords. Enfin l'abdomen est carene en dessus, et le sixieme anneau de cette portion du corps presente sur sa face dorsale deux fortes cretes terminees en forme de dent ; deux appendices styliformes tres forts representent le septieme anneau. La longeur du corps est de 9 centimetres, et la hauteur 3 centimetres. Dans la galerie du Museum, nous avons designe cet Amphipode sous le nom de Lysianassa magellanica." 8-2 6o DISCOVERY REPORTS Genus Lepidepecreum, B. and W. Stebbing, 1906, p. 78. Stephensen, 1925, p. 117. Lepidepecreum cingulatum, n.sp. (Fig. 22). Occurrence: St. 165. South Orkneys. 4 $$ (2 ovig.) 7-7-5 mm., from stomach of Notothenia. Description. Integument not strongly indurated (as preserved). Head with ocular angle almost rectangular, post-antennal angle obtusely quadrate. Eyes oval-reniform. Peraeon and pleon dorsally rounded, not at all carinate, and without any processes. Side-plates 1-4 deep, lower margins almost straight, and together forming an even line; excavation on 4 nearly rectangular, long (dorso-ventrally) but shallow; 5th deep, shallowly bilobed, posterior lobe slightly deeper and larger than anterior, 6th similar, Fig. 22. Lepidepecreum cingulatum, n.sp. a. Side-plate 4. b. Anterior margin of head with epistome and upper lip. c. Gnathopod 1. d. Gnathopod 2. e. Peraeopod 5. /. Telson. g. Pleon segments 3 and 4. 7th deeper than long, rounded below. Postero-inferior angle of pleon segment 1 rounded, of 2 quadrate, of 3 somewhat produced in an angle less than 90 , lower and hind margins almost straight. Telson longer than broad, cleft almost to centre, lobes apically subacute, each with one stout spine. Antenna 1, 1st joint carinate on dorsal edge, but not apically produced, flagellum n-12-jointed, accessory flagellum 5-jointed. Antenna 2, flagellum 13-14-jointed. Epistome and mouth-parts as figured for umbo (Sars, pi. xxxix, fig. 2) including the short stout spinules along inner margin of outer plate of maxilliped. Gnathopod 1 as in umbo, 2nd joint long, setose on front margin; but 5th and 6th joints stouter, the defining angle of concave palm more produced. Gnathopod 2 also as in umbo, but 6th joint more broadly oval, and chela minute. Peraeopods 1 and 2 slender. Peraeopods 3-5, 2nd joints ovately expanded, lower hind angle rounded, hind margin obscurely crenulate, 4th joints moderately expanded, 5th abruptly narrower. LYSIANASSIDAE 61 Uropods 1-3 extending back about equally, the inner ramus in each slightly shorter than outer ramus. Colour (as preserved) pale yellowish, with a greyish transverse band on each segment from peraeon segment 1 to pleon segment 5, extending on peraeon segments 1-5 only to the upper parts of the side-plates ; eyes black. Remarks. The resemblances of this form to umbo as regards the mouth-parts and 1st gnathopod appear to outweigh the absence of features usually found in the members of this genus, such as dorsal processes and the produced apex of the 1st joint of the 1st antenna. The feebly indurated integument may possibly be due to the specimens having been taken from a fish stomach, though they are in excellent condition and not at all mutilated or semi-digested. In longicorne there is a very similar segmental arrangement of pigment. Genus Lepidepecreella, Schell. Schellenberg, 1926, p. 281. Barnard, 1930, p. 321 (Paracyclocaris). Stephensen, 193 1 (Arkiv Z00L, xxn), pp. 1, 6. From the nearly related genera Lepidepecreum, Lepidepecreopsis , and the new genus described below, this genus is distinguished by the entire telson.The 4th side-plate is received into a definite groove on the 5th side-plate, as in Waldeckia. Lepidepecreella ovalis, n.sp. (Fig. 23). Occurrence: 1. St. 42. South Georgia. 1 $ 8 mm. 2. St. 45. South Georgia. 2 $$ 6-5 and 7 mm. Types. 3. St. 140. South Georgia. 2 $$ 7 and 8-5 mm. 4. St. WS 33. South Georgia. 1 $ 7 mm., 1 $ with embryos 8 mm. Description. Very close to ctenophora, Schell., but distinguished as follows : postero- inferior angle of pleon segment 3 with a tiny upturned acute point followed by a small and feeble semicircular notch (both features obscure in nos. 3 and 4) ; margin above very minutely and feebly serrulate ; telson longer than broad, ovate; uropod 3 with outer ramus half as long as peduncle, inner mar- gin minutely serrulate, 2nd joint minute, . , , , . . rig. 23. Lepidepecreella ovahs, n.sp. a. Pleon segment -! . inner ramus completely fused with pe- b _ TeIson . ,. Uropod 3, with apex of ramus further duncle; rostral process more prominent, enlarged, extending as far as apex of epistomal pro- jection; tooth on posterior margin of pleon segment 4 higher and more strongly developed. Integument indurated, strongly and closely punctured, especially on pleon segments 1-3. 62 DISCOVERY REPORTS Remarks. The above distinctive characters seem sufficient to justify a separate species. L. ctenophora was obtained by the 'Gauss' at her winter station, approx. 8ai° E, 66° S. Lepidepecreoides, Brnrd. Barnard, 1931, p. 426. Integument indurated. Body scarcely carinate anteriorly, but distinctly so posteriorly. Side-plates 1-5 deep; the 5th almost as deep as 4th, solid anteriorly, thin posteriorly, not grooved for reception of 4th ; 6th with a rather wide excavation between the anterior and posterior lobes; 7th longer than deep. Telson cleft to base. First joint of antenna 1 not carinate or apically produced. Epistome straight in profile, not expanded; upper lip gibbous. Mandible with palp inserted opposite molar, 2nd joint of palp not very elongate. Lower lip with lobes apically rounded. Gnathopod 1, 6th joint widening slightly distally, palm oblique. Gnathopod 2, 6th joint rather broadly oval, subchelate. Peraeopod 3, 2nd joint abnormally thick, angularly expanded in front and behind. Peraeopods 4 and 5, 2nd joints ovate, not abnormally thick. A single accessory branchia on both segments 5 and 6. Remarks. From its close allies— Lepidepecreum, B. and W., Lepidepecreopsis , Steph. 1925, and Lepidepecreella, Schell— this genus is easily distinguished by the unusually great depth of the 5th side-plate, and the unexpanded epistome. The mouth-parts agree with those of Lepidepecreopsis, the mandibular palp being inserted much more forward than in the other two genera. Lepidepecreoides xenopus, Brnrd. (Fig. 24). Barnard, 1931, p. 426. Occurrence: 1. St. 177. South Shetlands. 1 $ 11 mm. 2. St. 181. Palmer Archipelago. 1 $ 9 mm. Type. 3. St. WS 33. South Georgia. 1 juv. 4-5 mm. Description. Integument indurated ; when seen by transmitted light it has a honey- comb reticulation, but when seen in an oblique reflected light each hexagonal mark seems to have a raised border so that the integument appears strongly scabrous. Head with antero-lateral angle quadrate. No eyes. Peraeon moderately compressed, scarcely or feebly carinate, but dorsal profile indented at junctions of segments, especially pos- teriorly. Side-plates deep; 1-4 deeper than their segments, setulose on their anterior margins, 1-3 oblong, with a denticle at postero-inferior angle, 4 also oblong with the whole hind margin excavate for the reception of the deep 5th side-plate, which is very solid in front portion but with a crescentic hollowing posteriorly for reception of 2nd joint of peraeopod 3, hind margin and lower part of anterior margin setulose ; side-plate 6 slightly deeper than long, with lower margin excavate between anterior and posterior lobes; side-plate 7 longer than deep, ovoid; hind margins of 6 and 7 setulose. On segments 5, 6 and 7 just above the junction of the side-plates there is a rounded nodulose prominence. Pleon carinate, dorsal profile on each of segments 1-3 undulate, carina LYSIANASSIDAE 63 ending on segment 3 in a triangular tooth-like projection; segment 4 with a strong slender upstanding tooth; segment 5, very short; postero-inferior angles of segments 1-3 rounded. Segments 1-3 each have a lateral prominence which is rather indefinite, the most projecting part being in line with the prominences on peraeon segments 5-7. Telson twice as long as basal width, cleft to base, lobes tapering to acute apices, each with a terminal spinule. Antenna 1, peduncle stout but not carinate, the 1st and 2nd joints scabrous, 3rd very short, flagellum 6-jointed, 1st joint large, with regular brush of plumose setae along lower margin, 2nd-6th joints much smaller, accessory flagellum 2-jointed, as long as 1st flagellar joint, 1st joint long, 2nd very short. Antenna 2 slender, 4th and 5th joints subequal, flagellum 7-jointed. Fig. 24. Lepidepecreoides xenopus, Brnrd. a. General view, integumentary sculpture indicated on head and peraeopod 4. b. Profile of epistome and upper lip. c. Gnathopod 1. d. Gnathopod 2. e. 2nd joint of peraeopod 3 of juvenile (St. WS 33). Epistome straight in profile, not expanded; upper lip considerably gibbous. Mouth- parts as in Lepidepecreopsis (Stephensen, 1925, p. 120, fig. 33). Lower lip with lobes apically rounded as in Lepidepecreum. Spines on apex of outer plate of maxilla 1 very stout; inner plate with two setae. The short stout spines on apex of palp of maxilla 1 and on inner margin of outer plate of maxilliped very regular, as in Stephensen 's figures. Gnathopod 1 moderately slender ; 6th joint about two-thirds length (upper margin) of 5th, widening slightly to the oblique palm, a spine at the defining angle, finger over- lapping palm. Gnathopod 2, 6th joint ovoid, broader than in any of the allied genera, palm convex, slightly projecting, but not chelate, finger overlapping palm. Peraeopods 1 and 2 armed with a few rather long outstanding setae, dactyl elongate, two-thirds length of 6th joint (cf. Lepidepecreopsis). Peraeopod 3, 2nd joint remarkably thick, quadrangular, angularly expanded on both anterior and posterior margins, the 64 DISCOVERY REPORTS proximal part of anterior margin with a few spinules, the distal part and the whole posterior margin with short plumose setae, 3rd, 4th and 5th joints also with plumose setae as well as a few longer simple setae, dactyl slender, two-thirds length of 6th joint. In the juvenile the 2nd joint is more oblong than square and the hind margin is produced in a strong straight spine. Peraeopods 4 and 5, 2nd joints not abnormally thick, ovate, hind margin strongly serrate and with short plumose setae, armature of other joints as in peraeopod 3 ; peraeopod 4 slightly longer than 5. Uropods 1 and 2, rami subequal, acuminate, sparsely spinose. Uropod 3 extending as far back as uropod 1 and slightly beyond apex of telson, rami lanceolate, 2nd joint of outer ramus well developed, inner margin of both rami with long plumose setae. A single accessory branchia on both segments 5 and 6. Remarks. The extraordinarily shaped 2nd joint of peraeopod 3 fits within the hollowed portion of the 5th side-plate when the limb is folded back. The whole animal was covered with very fine particles of foreign matter due to the muddy nature of the bottom ; and the setulose margins of the side-plates would seem to be for the purpose of excluding such foreign matter from penetrating between them. Genus Allogaussia, Schell. Schellenberg, 1926, p. 245. The first species here described is very like the species of this genus described by Schellenberg, but shows the following peculiarities. Antenna 1 in both sexes very stout, 2nd joint of peduncle very short compared with its breadth, 3rd easily visible dorsally, but ventrally entirely masked on inner side by the 1st joint of flagellum, which is in continuity with the 2nd peduncular joint. First flagellar joint stout and elongate, 1st joint of accessory flagellum also elongate. Epistome expanding from quite near the bases of 1st antennae into a broad lamina, with a deep narrow notch separating it from the upper lip (the latter feature as in Allogaussia). Side- plate 4 fitting into a groove on side-plate 5, thus preventing the 2nd joint of peraeopod 3 from external movement over the posterior lobe of the latter. Uropod 3 extending slightly beyond apices of uropods 1 and 2, well developed, rami with marginal setae. Telson elongate, concave above. Accessory branchiae present on segments 5 and 6. Accessory branchiae are said to be absent in Allogaussia paradoxa, Schell. The man- dibular palp is inserted " far behind " (no figure given), and the palp of maxilla 1 in the new species has many more apical spinules than any of the three species described by Schellenberg. The locking of side-plates 4 and 5 and the confinement of peraeopods 3 and 4 to movement within the side-plates (as in Waldeckia and Kerguelenia) seems to be a greater specialization than is found in the original three species of this genus, where, according to Schellenberg's figures (1926, figs. 5 and 7), peraeopod 3 is freely movable outside and over the posterior lobe of the 5th side-plate. The epistome, telson and uropod 3 are not so very different, but the 1st antenna is entirely different and in conjunction with the character of the side-plates almost makes a separate genus advisable. LYSIANASSIDAE 6 S Schellenberg states that Allogaussia is near Orchomenella though he places it far away in his Gauss Report. He also refers to the likeness and possible identity of his A. litoralis (p. 249) with Orchomenella franklini, Wlkr. The relationship between both of Walker's species, pinguides and franklini, and the species of Allogaussia seem to be very close, and it is difficult to decide without material of the northern species for com- parison whether the former have been rightly referred to Orchomenella. Sars' figures of O. minuta and pinguis (1895, pi. xxiv, figs. 1 and 2), but not of ciliata (= nanus) and groenlandica (pi. xxv, fig. 2 and pi. xxvi, fig. 1), nor Bonnier's figures of laevis, show a very definite posterior lobe on the 5th side-plate and also a narrow projecting lobe on the 4th side-plate. Walker's figures of franklini (1903, pi. viii, figs. 31 and 35) show the same features and likewise the two species here described. But in the northern species the 2nd joint of peraeopod 3, though it appears (Sars, pi. xxiv, fig. 1, p 5 .) to be confined within the 5th side-plate, is not particularly expanded. Of what generic value are these characters? The epistome in the original species of Allogaussia and of the two here included is not greatly different from that of the typical species of Orchomenella. The epistome of Walker's two species is undescribed. 1 If pinguides and franklini be included in Allo- gaussia on account of peraeopod 3, then the form of telson ceases to be of generic importance, as there are both the short entire form (paradoxa) and the long form which may be either notched (naviada) or shallowly (litoralis) or deeply (pinguides and lobata) cleft. Further work on the points here raised is required, including a comparison of the northern and southern species of Orchomenella. Allogaussia navicula, n.sp. (Fig. 25). Occurrence: 1. St. 170. South S'letlands. 3 <$£, 4 ?? 7-8 mm. 2. St. 175. South Shetlands. 2 <$£ 8 mm., 2 ?$ 8-9 mm. Types. Description. Integument indurated, with scattered punctae. Body distinctly plumper in $ than in <$. Head with antero-lateral angle quadrate, but the actual angle rounded. Eyes large, narrow above, widening below, pale brown or reddish. Peraeon dorsally rounded. Side-plates deep, 1-3 oblong, rounded below, more so in 1 than in 3 ; 4 narrow, with long but rather shallow excavation, the posterior projection narrow, rounded, fitting into a slight groove on 5, which is ovate, deeper than long with a distinct posterior lobe but no anterior lobe; 6 oblong, the posterior lobe distinct; 7 deeper than long, rounded below. Pleon dorsally rounded, except for a low rounded medio-dorsal keel on segment 4 and 2 dorso-lateral keels on segment 6 projecting as two short rounded lobes on either side of telson ; postero-inferior angle of segment 1 rounded, of 2 quadrate, of 3 rounded-quadrate, margin entire. Telson oblong, twice as long as broad, slightly tapering, deeply concave dorsally like a gouge chisel, extending to about 1 In the Nimrod specimens of pinguides and franklini recorded in the Terra Nova Report (1930, p. 448), which certainly seem to agree with Walker's descriptions and figures, the epistome forms a strongly pro- jecting lamina, and side-plate 4 does not fit into a groove in side-plate 5. 66 DISCOVERY REPORTS middle of rami of uropod 3, apex truncate or slightly emarginate according as it is observed in its natural form or flattened, each apex with a spinule and a setule. Antenna 1 very stout, 1st joint obese, flattened on inside but dorsal margin not sharply keeled, 2nd joint very short, as broad as 1st, 3rd wider dorsally than ventrally, just visible ventrally on outside but on inside entirely masked by the 1st flagellar joint which is thus in continuity with the 2nd peduncular joint (cf. Kerguelenia antarctica, Brnrd., 1930, p. 318, fig. 1 b); flagellum 10-jointed, 1st joint stout, elongate, strongly setose on inner and lower surfaces, the other nine joints short, accessory flagellum 4-jointed, 1st joint elongate, lying in a groove on 1st flagellar joint, setose on its lower margin. No sexual difference except that there are eight short joints following the large 1st joint in ?. Fig. 25. Allogaussia navicula, n.sp. a. Antenna 1. b. Antenna 2 (3rd peduncular joint onwards), c. Mandible. d. Gnathopod 1. e. Side-plate 4. /. Side-plate 5 and 2nd joint of peraeopod 3. g. Side-plate 6 and 2nd joint of peraeopod 4. /;. 2nd joint of peraeopod 5. i. Telson. ;. Pleon segments 3-6. k. Uropod 3. /, Profile of epistome and upper lip. Antenna 2 slender, 4th joint longest, 4th and 5th strongly setose on upper margins, flagellum 10-jointed in <$, 9 in $. Epistome expanding from near bases of 1st antennae into a broad oblong lamina, rounded at upper and lower corners, separated by a deep curved groove from the upper lip, which is gibbous but not projecting beyond the epistome. Mandible, cutting edge somewhat rounded without any denticles, secondary cutting plate and spine row absent, molar well developed, rugulose, palp longer than trunk, inserted about in middle of trunk and behind molar, 2nd joint a little more than twice as long as 3rd, distal half of margin setose, 3rd joint nearly straight, margin setose. Maxilla 1, inner lobe narrow, acuminate, with two feeble apical setules, outer lobe with 8-9 serrate spines, palp ex- tending beyond outer lobe, its truncate apex with 9-10 short stout spinules. Maxilla 2 with both lobes narrow, subequal. Maxilliped, inner plate acuminate, without apical spines, outer plate extending to just beyond apex of 2nd joint of palp, inner margin with LYSIANASSIDAE 67 crenulations passing into 2-3 separate stout spines on apex, palp 4-jointed, 4th joint slender. Gnathopod 1 subchelate, 2nd joint straight, setose on anterior margin, 5th rather elongate triangular, lower distal projection narrow, 6th oblong, parallel-sided, twice as long as broad, palm transverse, straight or slightly concave, or even slightly convex, obscurely crenulate, with 1-2 spinules at angle, finger slender, slightly overlapping palm. Gnathopod 2 minutely chelate, 6th joint shorter than 5th, oblong. Peraeopod 3, 2nd joint subcircularly expanded, hind margin obscurely notched, 4th joint not strongly expanded. Peraeopod 4, 2nd joint ovate, anterior margin straight, hind margin obscurely notched. Peraeopod 5, 2nd joint ovate, but more strongly expanded than in peraeopod 4. Uropods 1 and 2, rami subequal, acuminate, with a few spinules. Uropod 3 extending slightly beyond apices of uropods 1 and 2, and beyond telson, upper outer margin of peduncle rather expanded, convex, upper inner margin straight, with 2 spinules, inner ramus, which is actually inserted above the outer ramus, as long as 1st joint of outer, inner margins of both with plumose setae in both sexes. A single elongate accessory branchia on both segments 5 and 6. Allogaussia lobata, n.sp. (Fig. 26). Occurrence: 1. St. 142. South Georgia. 1 juv. 5-5 mm. 2. St. 170. South Shetlands. 1 ? 13 mm. Type. 3. St. 208. South Shetlands. 2 $$ 9-10 mm. Description. Like navicula, but larger. Eyes pale reddish. Side-plates as in naviatla. Pleon segment 3 very similar to that of navicula as regards postero-inferior angle ; seg- ment 4 with a more prominent dorsal keel which ends posteriorly in a rounded lobe Fig. 26. Allogaussia lobata, n.sp. a. Telson. b. Pleon segments 3-6. c. Profile of epistome and upper lip. d. 2nd joint of peraeopod 3. overlapping segment 5 ; segment 6 with the dorso-lateral keels on either side of telson more prominent. Telson longer than wide, cleft for two-thirds its length, the lobes dehiscent, each with an apical spinule. Antennae 1 and 2, and mouth-parts as in navicula. Epistome not expanded proxi- mally, its profile sinuous. 68 DISCOVERY REPORTS Gnathopod i, palm slightly convex, crenulate. Peraeopod 3, 2nd joint strongly expanded into a rounded lobe. In other respects, including presence of an accessory branchia on segments 5 and 6, like navicula. Remarks. Considerably larger than any of the other species (including also pingnides and franklim). The specific name refers to the 2nd joint of peraeopod 3, the carinae on segments 4 and 6, and the distinct lobes of the telson. Genus Orchomenella, G. O. Sars. Sars, 1891-95, p. 66, and p. 73 (Orchomenopsis). Stebbing, 1906, p. 81, and p. 83 (Orchomenopsis). m Fig. 27. Dorsal profiles of pleon segments 3 and 4 (also segments 5 and 6 in a) of species of Orchome- nella and Orchomenc. a. Orchomenella acanthurus, Schell. b. abyssorum (Stebb.). c. rolundifrons, n.sp. d. macronyx, Chevr. e. rossi (Wlkr.). /. charcoti (Chevr.). g. cavimanus (Stebb.). /;. zschauii (Pfr.). i. nodimanus (Wlkr.). ;'. pinguides, W\kr. k.franklini, Wlkr. /. chelipes, Wlkr. m. Orchomene goniops, W\kr. (Figs, i-tn are from drawings from the type specimens in the British Museum kindly made by Dr I. Gordon.) As Stebbing says in his key (1906, p. n) there are no constant differences between the two genera, and with the discovery that O. zschauii possesses a projecting epistome together with the 2nd antennae considerably longer than the 1st antennae, the differences hitherto relied upon are obliterated. LYSIANASSIDAE 69 Orchomenella cavimanus (Stebb.) (Fig. 27 g). Stebbing, 1888, p. 679, pi. xxii. Schellenberg, 1926, p. 285, fig. 25. Occurrence: 1. St. 51. Falkland Islands. 4 6*6* 8 mm., 12 $$ (incl. specimens with ova and embryos) 8-10 mm., 5 juv. 6-7 mm. 2. St. 152. South Georgia. 1 ? 10 mm. Remarks. Eyes pale brown. Epistome and upper lip as in Stebbing's figure. Pleon segment 4 as in Schellenberg's figure. The 2nd antennae are distinctly longer than the 1st in Fig. 30. Orchomenella rotundifrons, n.sp. a. Profile of epistome and upper lip. b. Proximal joints of peraeopod 3. c. Gnathopod 1. d. Gnathopod 2 (setae omitted), e, Telson. Gnathopod 1, 6th joint stout, narrowing distally, palm short, transverse, gently con- vex, entire, defined by one spine; finger short, stout, matching or only slightly over- lapping palm. Gnathopod 2, 6th joint moderately broad, minutely chelate. Peraeopod 3, 2nd joint very strongly expanded, subcircular, hind margin slightly serrate. Uropod 3, inner ramus not reaching the 2nd joint of outer ramus, inner margins of both with plumose setae, outer margins spinose. Remarks. It seems necessary to institute a new species for these specimens, which will not fit into any of the described ones. They might be referred to proximo, Chevr., except that Chevreux does not specially mention the carination on pleon segment 4, comparing his specimens with obtiisa, Sars, where the carina is of quite a different shape. Moreover the postero-inferior angle of pleon segment 3 is distinctly rounded in obtiisa. The objections to referring them to nodimamis , Wlkr ., are that the hand of gnathopod 1 has no tubercle on the lower margin, and the shape of the carina on pleon segment 4 is quite different (see Fig. 27 1). LYSIANASSIDAE 73 Orchomenella acanthurus (Schell.) (Figs. 27 a, 31). Schellenberg, 193 1, p. 47, fig. 25. Occurrence: 1. St. 141. South Georgia. 1 ovig. $ 10 mm. 2. St. 145. South Georgia. 1 ovig. $ 13 mm. 3. St. WS 33. South Georgia. 1 juv. 7 mm. 4. St. MS 62. South Georgia. 2 juv. 5-6 mm. Description. Body plump. Integument indurated. Head with antero-lateral angle quadrate. Eyes oval, wider below, black. Side-plates deep, one parallel-sided, rounded below, five nearly evenly bilobed, the posterior lobe only a little deeper than anterior, peraeopod 3 therefore freely movable outside the side-plate. Pleon segment 3 with dorsal profile less convex than usual, posteriorly subcarinate, and ending in a square, almost pointed, projection, postero- inferior angle quadrate ; segment 4 with a high acute triangular process following the inden- tation. Telson ovate, scarcely half as long again a "■ as wide, cleft for a little over half its length, lobes Fi g- 3 1 - Orchomenella acanthurus (Schell.). tapering to acute apices with a spinule in a notch a ' ^ rofile of e P istome and u PP er U P" *• Gnatho " .. - . , , 1.1 pod 1, with palmar denticles further enlarged, on outside or apex, and three lateral spinules. c jelson Antenna 1, 1st joint stout, 2nd and 3rd short, flagellum 9-jointed, 1st joint long, accessory flagellum 6-jointed, 1st joint also long. Antenna 2 a little longer than antenna 1, flagellum 13-jointed. Epistome produced in a broadly rounded lobe projecting beyond the upper lip. Gnathopod 1, 6th joint distinctly narrowing distally, palm transverse, defined by two spines, its margin with minute squarish denticles, finger overlapping palm. Gnathopod 2, 6th joint minutely chelate. Second joint in peraeopod 3 broadly expanded, in peraeopod 4 less so, in peraeopod 5 again broadly expanded; hind margins of all feebly notched. Uropod 3, inner ramus extending to apex of 1st joint of outer ramus, margins of both rami spinulose. Remarks. An easily recognized species. The carination of the 3rd pleon segment, raised above the insertion of segment 4, is interesting. Orchomenella zschauii (Pfr.) (Fig. 27 h). Pfeffer, 1888, p. 87, pi. ii, fig. 1. Stebbing, 1906, p. 85 (part). Shoemaker, 1914, p. 73. Schellenberg, 1931, p. 46, fig. 24. Occurrence: 1. South Georgia. 3. iv. 25. Many $$ and $$ 9-13 mm. 2. East Cumberland Bay, South Georgia. 30. xii. 26. 11-36 m., 2 $? 9 and 12 mm. 74 DISCOVERY REPORTS Remarks. The collection of specimens agreeing exactly with Pfeffer's description and figures, and from the same locality, is welcome, as it enables one to vindicate Pfeffer's specific name, and the systematic position assigned to it by Stebbing in 1906, as well as to describe the only two important structural details which Pfeffer omitted to mention. Shoemaker has already reported the species (under the name Waldeckia zschauii) from the Bay of Isles, South Georgia, but beyond clearly stating that the specimens agreed with Pfeffer's species and not with Chevreux's obesa, he did not further discuss it. The epistome is distally gibbous, as in Stebbing's figure of that of cavimanus (1888, pi. xxii). One of the distinctions between Orchomenella and Orchomenopsis therefore breaks down. The 2nd antennae are elongate in the $ as described by Pfeffer. The finger of gnathopod 2, though overlooked by Pfeffer amongst the thick terminal brush of setae, is present ; it is rather small and impinges against the slightly projecting lower distal corner of the 6th joint, as it does in cavimanus; there is also an indication of the little projecting process or platform figured by Schellenberg (1926, fig. 25 b) for the same species, but not so prominent. This raises the question whether cavimanus should not be considered synonymous, as Stebbing himself thought in 1906. Schellenberg, however, maintains cavimanus as distinct, and in my opinion he is undoubtedly right. The peculiar shape of the dorsal profile of pleon segment 4 is quite distinctive and constant. A glance at the figures of the two species here given will show that there is no possibility of confusion. In cavimanus the highest point of the keel is vertically above the posterior margin of the segment, whereas in zschauii it is much more forward. As Schellenberg (1926) remarks for cavimanus, there is a tendency for the branchial lamellae to develop transverse pleats. A single accessory branchia is found on both segments 5 and 6. The telson is cleft nearly to the base and the lobes though parallel are separated by a narrow space, as in Pfeffer's figure ; each lobe has a terminal spinule and two lateral spines. Distribution. South Georgia. The specimens from Coats Land recorded by Chilton as Waldeckia zschauii are not this species but W. obesa. Genus Pseudorchomene, Schell. Schellenberg, 1926, p. 295. Distinguished by the slender 1st gnathopod. Pseudorchomene coatsi (Chilton). Chilton, 1912, p. 477, pi. i, figs. 8, 9 (Orchomenopsis ?). Schellenberg, 1926, p. 295. Occurrence: 1. St. 41. South Georgia. 1 $ 9 mm., 2 $$ (1 ovig.) 13 mm. 2. St. 42. South Georgia. 3 ovig. $$ 12-14 mm. 3. St. 45. South Georgia. 1 $ 11 mm., 1 $ 13 mm. 4. St. 142. South Georgia. 2 <$<$ 10-11 mm., 1 ovig. $ 13 mm., 7 juv. 5-8 mm. 5. St. 154. South Georgia. 1 $ 10 mm. LYSIANASSIDAE 75 Remarks. Both in the dorsal profile of pleon segment 4 and the non-projecting epistome this species resembles rossi, but the slender 1st gnathopod and reddish brown eyes at once distinguish it. A single accessory branchia on both segments 5 and 6. Distribution. Coats Land, 161 fathoms; 'Gauss' winter station, 385 m. Genus Pachychelium, Steph. Stephensen, 1925, p. 121. Schellenberg, 1926, p. 296; 1931, p. 18. To help towards a complete definition of this genus, it may be stated that the mandible has a non-dentate cutting edge, no molar, and a well-developed palp ; maxilla 1 bears 3-4 strong teeth on the outer lobe, one spine seta on the inner lobe, and lacks all trace of a palp. Pachychelium davidis, Steph. (Fig. 32). Stephensen, 1925, p. 121, fig. 35. Schellenberg, 1926, p. 296, fig. 30 {antarcticum). Occurrence: 1. St. 39. South Georgia. One specimen 3-5 mm. 2. St. 58. Falklands. One specimen (? 1 ? with uterine ova 24 mm., 6 immat. 12-14 mm., 14 juv. 4-10 mm. 4. St. 72. South-west Atlantic. 5 $$ 16-20 mm. 5. St. 76. South-west Atlantic. 1 S 19 mm., 2 $$ 22 mm. 6. St. 78. South Atlantic. 1 immat. 14 mm. 7. St. 85. South-east Atlantic. 3 $$ 18 mm., 2 immat. 15 mm. 8. St. 101. South Africa. (1310-1410 m.) 1 $ 16 mm. 9. St. 107. South-east Atlantic. 1^15 mm., 1 $ 22 mm. 10. St. 114. Bouvet Island. 1 $ 19 mm., 10 $$ 18-28 mm., 4 juv. n-15 mm. n. St. 151. South Georgia. 1 immat. 13 mm. 12. St. 208. South Shetlands. 2 immat. 8 and 1; mm. 78 DISCOVERY REPORTS 13. St. 239. South-west Atlantic. 11 So 15-22 mm., 11 ?$ 17-24 mm., 1 ? with embryos 26 mm., 6 immat. 11-15 mm. 14. St. 253. South-east Atlantic. i$i6mm. 15. St. 256. South-east Atlantic. 1 mutilated, 1 immat. 12 mm. 16. St. 287. Mid-Atlantic. 2 c?c? 13 and 14 mm., 1 ? 12 mm., 2 juv. 6 and 9 mm. 17. St. 298. Cape Verde. 1 $ 16 mm. Description. The integument is not covered with "hexagonal markings", but is speckled all over with minute points as represented in Stebbing's figure of side-plate 1 (1888, pi. xxxvi, gn-^). Eyes completely obsolete. Side-plate 1 triangular, deeper than its basal length; side-plate 4, i\ times deeper than its greatest length (just below the Fig. 35. Parandania boecki (Stebb.). a. Maxilla 1 (whole inner margin of inner lobe with long plumose setae), b. Peraeopod 4. c. Peraeopod 5, with lower hind margin of 2nd joint further enlarged, d. Side-plate 4. e. Pleon segments 2 and 3. posterior excavation). Pleon segment 2 with postero-inferior angle quadrate ; segment 3 acutely produced. Antenna 1, flagellum about 20-jointed, 1st joint densely setose, accessory flagellum nearly bare, without long terminal setae. Antenna 2, flagellum about 35-jointed. Epistome carinate. Maxilla 1, with an acute projection on outer side of insertion of palp (probably invisible if the appendage were squashed under a coverslip). Peraeopods 3 and 4, 6th joint almost equal to 4th and 5th joints together, quite equal if the dactylus be included, slender, minutely spinulose. Peraeopod 5, 2nd joint ovate, anterior margin proximally gibbous, but not strongly so, distal hind angle considerably more pointed than in Stebbing's figure. Uropods 1 and 2, peduncle carinate on ventral surface. Uropod 3, peduncle carinate on dorsal surface. Both margins of outer ramus and inner margin of inner ramus of STEGOCEPHALIDAE 79 uropod i minutely serrulate or pectinate; inner margin of outer ramus, and outer margin of inner ramus, in uropods 2 and 3 also minutely serrulate or pectinate. Remarks. Although there are a few specimens which exactly fit the Challenger specimen, the great majority differ slightly as regards the characters set out above. The length of the dactyls of peraeopods 3 and 4 is the most noteworthy difference. It seems that the normal form is as here described and that the Challenger specimen was ex- ceptional. The specimens with short dactyls are mostly smaller specimens, but the length of the dactyls is not dependent on growth changes, because quite small specimens (e.g. juveniles of no. 3) have the typical elongate dactyls. Intermediate lengths also occur. Schellenberg (1926 b) has figured a peraeopod "6" (= 4) with long dactyl in connection with his remarks on bathypelagic adaptations. On most occasions hitherto this species has been captured only singly, whereas the 'Discovery' on several occasions has taken it in fair numbers, viz. 15, 29 and 31 at a time. All the specimens are more or less brown in colour, though some are somewhat bleached. No. 3 is recorded as being "very dark brown", and Note 20 at St. 8 says "jet black in front, abdomen purplish black". The embryos from the brood pouch of no. 13 are white. This brown or blackish colour is found also in E. gigantea, A. abyssi and other Stegocephalids. The eyes are completely obsolete. No traces of ocular pigment were visible in any of the specimens, and the optic nerve and ganglion are quite absent. A similar condition was found in the specimens identified by Strauss as Andaniexis abyssi (1909, p. 78). I very much doubt this identification; the size, nearly 20 mm., is against their being A. abyssi, whereas it is in favour of their being P. boecki, which is now known to have a wide distribution in southern waters. Strauss was not a systematist and has perpetrated several synonyms and nomina nada ; it is a pity he did not have his specimens properly identified, especially as he has called the stage of complete degeneration of the eye the "Andaniexis" stage. The true Andaniexis has at least ocular pigment (Sars, 1895), and so far as we know may still retain rudiments of the visual elements and optic ganglion. A re-examination of Strauss' material is desirable, as Schellenberg has shown in regard to the Gauss and Valdivia collections, which Strauss also worked. The $ with embryos was caught in June, that with uterine ova in May ; the Cape ? with ova (Barnard, 1916) was caught towards the end of April. The breeding season would thus seem to be autumn and winter in the southern hemisphere. There is no evidence of a nocturnal upward migration. Our knowledge of the distribution in the south-westerly portion of the Atlantic has been considerably extended, the most southerly locality being 53 25' S off South Georgia, though in the easterly portion of the Atlantic the 'Valdivia' recorded this species from 55 20' S. Distribution. North Atlantic (Bay of Biscay to equator); South Atlantic (off Pernambuco and south to 55 S); Indian Ocean; South Africa. So DISCOVERY REPORTS Genus Euandania, Stebb. Stebbing, 1906, p. 97. Euandania gigantea (Stebb.). Stebbing, 1888, p. 730, pi. xxxv; 1906, p. 97. ? Walker, 1907, p. 18. Occurrence: St. 85. South-east Atlantic. 1 $ 33 mm. Remarks. As preserved the integument is very flimsy, and the colour a pale horn colour. The rami of uropod 3 extend as far as those of uropod 1 , and are similar in character. Walker's record remains unconfirmed ; he himself recorded the species with a query, as he did not dissect the specimen. Distribution. Off Marion Island, 2926-3430 m. McMurdo Sound? Genus Andaniotes, Stebb. Stebbing, 1906, p. 96. Barnard, 1930, p. 328. Fig. 36. Andaniotes linearis, n.sp. a.Peraeo- Andaniotes linearis, n.sp. (Fig. 36). Occurrence: 1. St. 39. South Georgia. 1 $ 7 mm. 2. St. 42. South Georgia. 3 ovig. ?2 5-5- 6 mm. 3. St. 144. South Georgia. 2 ?? (1 ovig.) 11 mm. 4. St. 148. South Georgia. 1 $ 10 mm. 5. St. 149. South Georgia. 1 ovig. $ 11 mm. 6. St. 156. South Georgia. 6 $$ 9-10 mm. (1 with one embryo left in pouch). Types. 7. St. 175. South Shetlands. 1 $ 9 mm. 8. St. 190. Palmer Archipelago (90-130 m.). pod 5. b. Peraeopod 4 (dotted lines indicate 1 $ 7-5 mm., 1 ovig. $ 8 mm. a ridge with setae on inner surface). _ >rr . ... c. Peraeopod 3. Description. Differing from corpiuentus in its larger size, in the linear 2nd joint of peraeopod 4, the almost smooth hind margin of 2nd joint of peraeopod 5 , and the slender evenly tapering 6th joint of gnathopod 2. From ingens it differs in not showing any sign of the degeneration of the palp of maxilla 1 or the palp of the maxilliped, or shortening of the mandibles, being in these respects quite like corpulentus. Remarks. It is possible that the specimens from Port Charcot recorded by Chevreux (1906, p. 22) as corpulentus, an Australasian species, should really belong here. AMPELISCIDAE 81 Family AMPELISCIDAE Stebbing, 1906, p. 97. Strauss, 1909, pp. 20-36 (eye structure). Barnard, 1916, p. 132; 1925, p. 335; 1930, p. 329. Three of the four known genera are now found to be represented in the Antarctic. The South African Triodos, Brnrd., was instituted to express the breakdown of the generic definitions which up to that time were clear cut, though Byblis anisuropus, Stebb. 1908, showed a slight anomaly. The Antarctic fauna is now shown to possess a Haploops with an expanded 2nd joint in peraeopod 5 as in Ampelisca and Byblis ; the type of a new genus with rather distinctive features of its own, together with characters of Ampelisca and Byblis; also two forms with simple branchiae, a character which is in conflict with the hitherto accepted definition of the family. Finally, the Haploops which has been brought to light by the ' Discovery ' has the lower pair of corneal lenses on the ventral surface of the head, as in A. hemicryptops recently described from the Terra Nova collection. Genus Ampelisca, Kroy. Stebbing, 1906, pp. 98, 721. Barnard, 1916, p. 132; 1925, p. 335; 1930, p. 329. Ampelisca eschrichtii, Kroy. (Fig. 37 a). Chevreux, 1906, p. 20, fig. 11 ; 1913, p. 96. Occurrence:!. St. 42. South Georgia. 1924 mm. 2. St. 144. South Georgia. 1 <$ 22 mm., 2 ovig. ?$ 21 and 25 mm., 6 juv. 10-1 1 mm. 3. St. 180. Palmer Archipelago (160 m.). 3 $? 20-23 mm. 4. St. 187. Palmer Archipelago. 2 ?$ 21 and 23 mm. Remarks. On the question of the identity of the northern and southern forms see Chevreux (1906), Chilton (19 17, Joum. Zool. Res., xi, p. 75) and Stephensen (1925, p. 140). Stappers and Stephensen are able to dis- tinguish macrocephala from eschrichtii and these two species are very distinct in Sars' figures. A fortiori I fail to see how it is "■ possible to include either acinaces or chiltoni in Fig> Th ° utline of head of : a - Am P e &™ eschrichtii, , ■ , ,.. rr,, , j 1 i- 1 Kroy.; b. hemicrvptups, Brnrd. eschrichtii. lhe more evenly rounded hind margin of the 2nd joint of peraeopod 5 and the stronger dorsal keel on pleon segment 4 seem to be sufficient to distinguish the southern form, though in the opinion of some authors these may not constitute specific characters. I entirely agree with Stephensen. and think that a new name should be found for the southern eschrichtii. The 2nd joint of the mandibular palp is linear in the southern as in the northern form. Distribution. Palmer Archipelago, 60-200 m. 82 DISCOVERY REPORTS Ampelisca macrocephala, Lilj. (Fig. 38). Walker, 1903, p. 53, pi. ix, figs. 58-61*; 1907, p. 18. Stebbing, 1914, p. 357. Occurrence: 1. St. 42. South Georgia. 2 <£ South Orkney Islands. Heterophoxus trichosus, n.sp. (Fig. 50). Occurrence :St. 175. South Shetlands. 1 2 12 mm. Description 2. Body dorsally rounded, setose on the posterior peraeon segments and on pleon segments 1-3 . Head with hood apically rounded (cf . Harpinia plumosa , Sars, pi. Hi). Eyes small, narrow oval, black. Side- plate 4 with shallow but better marked excavation than in pennatus Shoem. Pleon segment 3 with postero-inferior angle pro- duced in an upturned acute process. Telson as in videns, Brnrd., with 2-3 setae on apex of each lobe. Antenna 2 of the Harpinia type; basal joint with curved ensiform process as in pennatus, videns and Harpinia cariniceps. Fig. 50. Heterophoxus trichosus, n.sp. a. Pleon seg- ments 3 and 4. h. Peraeopod 5. PHOXOCEPHALIDAE 101 Gnathopod i, 5th joint rather larger proportionately than mpennatus. Peraeopod 5, 2nd joint considerably more broadly expanded than in either pennatus or videns, hind margin with sharp serrations, anterior margin of lobe facing the 3rd and 4th joints slightly concave, the lower anterior angle rounded-quadrate, 4th joint lobed on hind apex as in videns. Remarks. This species resembles the genotype pennatus, Shoem., very closely, but is distinguished by the 5th peraeopod and 4th side-plate. From the other Antarctic species the acutely produced postero-inferior angle of pleon segment 3 easily distinguishes the new form. Genus Parharpinia, Stebb. Stebbing, 1906, p. 147. Tattersall, 1922, p. 4. Tattersall has doubted the value of the characters used to separate Parharpinia from Pontharpinia. The expansion of the 4th and 5th joints of peraeopods 3 and 4 certainly seems to show gradations. The following species are typical Parharpinia according to Stebbing's diagnosis. Parharpinia obliqua, n.sp. (Fig. 51). Occurrence: 1. St. 136. South Georgia. 1 <$ 11 mm. 2. St. 175. South Shetlands. 1 ? 15 mm. Description. Body dorsally rounded, glabrous. Hood flattened, apex in dorsal view rounded (cf. Sars, pi. li, Paraphoxns ocidatns). Eyes black, in S large, obliquely ovate, nearly meeting dorsally, in $ small, oval. Side-plates 1-4 fringed with setae on lower margin; 1 scarcely widened below, 4 as deep as long, excavation shallow. Postero- inferior angle of pleon segment 3 rounded, with an oblique row of long spine-setae; segment 4 with evenly rounded dorsal profile. Telson with the lobes apically rounded, a spine and a setule in a little notch towards the outer margin. Antenna 1, 2nd joint with long setae on lower margin in $, flagellum 12-jointed in S, 1 1 -jointed in ?, accessory flagellum 8-jointed in 6*, 7 in ?. Antenna 2, 4th joint expanded below, but width not more than two-thirds length, lower margin with very long spine- setae, upper margin in ? with some long setae on inner side, on outer side a series of about 14 very strong outstanding spines, in $ with thick fringe of setae, 5th joint in $ also with very long setae on lower margin and strong outstanding spines on upper outer margin, the latter consisting of 4 in the middle of the joint, 2 towards the apex, in $ upper margin with 8-9 fascicles of setae and 8-9 calceoli, flagellum 12-jointed in ?, multiarticulate and calceoliferous in S- Third palpal joint of mandible equal to 1st and 2nd together. Maxilliped, outer plate easily extending beyond middle of 2nd joint of palp, fringed on inner margin with about 12 graduated serrate spines, with 2-3 plumose spine-setae distally. Gnathopods 1 and 2, similar to Tattersall's figure of villosa (1922, pi. i, figs. 9, 10) but 5th joint in gnathopod 1 measured along its upper margin nearly as long as 6th joint. 102 DISCOVERY REPORTS Peraeopods i and 2, 4th joint stout as in villosa. Peraeopod 3, 2nd joint pyriform, anterior margin straight, with a few long setae, posterior margin gently convex, with minute setules, 4th and 5th joints nearly as villosa. Peraeopod 4, 2nd joint stout, anterior margin angularly rounded, strongly setose, especially distally where the setae are plumose and form a thick fringe, hind margin slightly concave in $, straight in g, with a small rounded lobe distally. Peraeopod 5, 2nd joint almost subcircularly ex- panded, extending to end of 4th joint, margin shallowly notched, 3rd joint somewhat lobed on anterior apex, 4th with anterior margin convex, hind apex produced in a short acute lobe. Fig. 51. Parharpinia obliqua, n.sp. a. Telson. b. Pleon segments 3 and 4. c. Peraeopod 3. d. Peraeopod 4 ?. e. Peraeopod 5. (Setae in c, d, e omitted.) Uropod 2, peduncle fringed with upstanding spines on upper margin. Uropod 3, peduncle with a half circlet of spines around the lower apex, inner ramus two-thirds length of outer in $, in £ rami subequal, much enlarged, with long plumose setae. Remarks. Stebbing has recorded the Australian Pontharpinia rostrata (Dana) from the Falkland Islands (1914, p. 357), but the present species will not fit in with his 1906 diagnosis as regards the maxilliped, gnathopods and 3rd~5th peraeopods. The cha- racters of peraeopods 3-5 also differentiate it from the West Australian specimen which Tattersall referred to villosa. It bears a close resemblance to Paraphoxas pyripes, Brnrd. (1930, p. 332, fig. 10), as regards peraeopods 3-5, though the postero-inferior angle of pleon segment 3 is quad- rate in the latter; the present form, however, has a 2-jointed palp on maxilla 1. The S was caught near the surface in a night haul. The specific name refers to the oblique row of setae on the epimeron of pleon segment 3. PHOXOCEPHALIDAE 103 Parharpinia sinuata, n.sp. (Fig. 52). Occurrence: 1. St. 159. South Georgia. 1 $ 14 mm. Type. 2. St. WS 88. Cape Horn. 1 $ 11 mm., 1 juv. 8 mm. Description ?. Distinguished from obliqua by the following characters. Hood more sharply pointed. Eyes considerably larger. Pleon segment 3 with postero- inferior angle rounded, with a slight emargination above, set with a graduated series of setae; no oblique row of setae on the lateral surface. Gnathopods 1 and 2, 5th joint longer proportionately to 6th; in gnathopod 1 it is equal to 6th, in gnathopod 2 almost equal to 6th (measured along upper margin). Peraeopod 3, 2nd joint not markedly pyriform, the hind margin evenly convex. Peraeopod 4, 2nd joint not angularly but evenly convex on anterior margin, more Fig- 5 2 - Parharpinia sinuata, n.sp. a. Dorsal view of head. b. Pleon segments 3 and 4 (of type), c. Postero- inferior corner of pleon segment 3 (St. WS 88). d. 2nd joint of peraeopod 3. e. 2nd joint of peraeopod 4. /. Peraeopod 5. (Setae in d, e,/omitted.) strongly spinose, but with a feeble fringe of plumose setae at apex, or none at all, hind margin straight, not concave, with a larger rounded lobe at hind apex. Peraeopod 5, 3rd and 4th joints with anterior margin straight, not lobed or markedly convex, 4th not produced on hind apex. Remarks. Like the previous species this differs from villosa; in fact considerably more so, because of the greater length of the 5th joint in both gnathopods. In this latter respect it somewhat resembles Protophoxus australis, Brnrd., but there the 5th joint is much more slender. The specific name refers to the slight sinuosity of the hind margin of pleon segment 3 . The position of this slight sinus with its group of setae varies ; in the type it is low down and the angle of the segment is consequently narrowly rounded; in the other two specimens it is higher up and the angle is broadly rounded. The other characters are identical, so that one must regard this feature as variable. 104 DISCOVERY REPORTS The description of the postero-inferior angle of pleon segment 3 given by Stebbing (1906, p. 146) for Pontharpinia rostrata might perhaps apply here. But I am unwilling to identify the Discovery specimens with the Australian rostrata, in spite of Stebbing's record of it from the Falkland Islands, until the Australian forms pinguis, rostrata and villosa have been given an exact status. Parharpinia rotundifrons, n.sp. (Fig. 53). Occurrence : 1 . St. 39. South Georgia. 1 $9 mm. Type. 2. St. 141. South Georgia. 1 2 8 mm. 3. St. WS 25. South Georgia. ijuv.4-5mm. Fig- 53- Parharpinia rotundifrons, n.sp. a. Dorsal view of head. b. Pleon segments 3 and 4. Description 2. Differing from the preceding species as follows. Hood broadly rounded in front. Pleon segment 3 with postero-inferior angle produced in a rather narrowly rounded lobe, slightly concave on its upper margin which bears 3-4 minute spinules. Gnathopods 1 and 2, proportions of 5th joint to 6th intermediate between obliqua and villosa (as figured by Tattersall), i.e. in gnathopod 1, 5th joint is three-quarters length of 6th, in gnathopod 2 half its length. Peraeopods 3-5 as in sinuata, but anterior margin of peraeopod 4 more strongly convex. Family AMPHILOCHIDAE Barnard, 1916, p. 143; 1930, p. 337. Schellenberg, 1926, p. 301 ; 193 1, p. 92. Genus Gitanopsis, G. O. Sars. Stebbing, 1906, p. 153. Barnard, 19 16, p. 144. Schellenberg, 1926, p. 301 ; 193 1, p. 95. Gitanopsis antarctica, Chevr. Chilton, 1912, p. 479. (Amp/iiloc/iits squamosus, nun Thorns.) Chevreux, 1913, p. 104, figs. 13-15. Schellenberg, 1926, p. 301. (Amphilochus squamosus, non Thorns.) Occurrence: St. MS 67. South Georgia. 1 ovig. 2 4 mm. Remarks. Although Chilton has united antarctica with the New Zealand Amphilochus squamosus, and Schellenberg has accepted this, I think it better to suspend judgment for the present. No detailed modern figures of the New Zealand form have been given, and the uniting of the two forms rests on the individual opinion of one author: " I cannot find any character of importance. . .". (Chilton, 1923, Trans. N.Z. Inst. LIV, p. 240.) Another reason for not following Chilton is that he also included marionis, Stebb., in the synonymy, to which Schellenberg, quite rightly in my opinion, does not subscribe. AMPHILOCHIDAE : LEUCOTHOIDAE ,o S Colour (as preserved) pale horn-coloured, with numerous maroon specks over head, peraeon, pleon, side-plates and 2nd joints of peraeopods 3-5, eyes dark brown. Distribution. Petermann Island, 3 m.; South Orkneys; Kerguelen. Hoplopleon, n.g. Close to Peltocoxa but with mandibular palp absent, pleon segment 4 very long, telson short, and accessory flagellum of antenna 1 absent. The finding of a second species closely allied to Peltocoxa australis, Brnrd., and ex- hibiting the same features which distinguish the latter from the true European Peltocoxa, renders a new genus necessary. The genotype is Peltocoxa australis, Brnrd. 1916. Hoplopleon medusarum, n.sp. (Fig. 54). Occurrence: Hoetjes Bay (Saldanha Bay), South Africa. 5. x. 26. o m. from Medusae. Fig- 54- Hoplopleon medusarum, n.sp. a. Gnathopod 1, with spine further enlarged. b. Gnathopod 2. c. Pleon segments 3-6. Description. Very closely resembling australis, except in gnathopods 1 and 2 and peraeopods 4 and 5 . Gnathopod 1 , 5th joint with 6-7 strong spine-setae on lower margin and apex, 6th joint ovate, palm ill-defined, with 4 strong spine-setae, finger with spinules along inner margin and a denticle near apex. Gnathopod 2, 5th joint with 6 strong spine-setae on lower apex, 6th widening slightly to the transverse concave palm, defining angle rounded, with 4 strong spine-setae. Peraeopods 4 and 5, 2nd joint with hind margin convex, not straight or nearly so as in australis, the contrast most noticeable in peraeopod 4. Remarks. Whereas the specimens of australis were found amongst littoral Hydroids, Algae, etc., the present specimens were extracted from a jellyfish. Family LEUCOTHOIDAE Stebbing, 1906, p. 161. Schellenberg, 1928 (Jr. Zool. Soc. Loud., 1928, pt. 5), p. 635 (new genus). Genus Leucothoe Leach. Stebbing, 1906, pp. 163, 724. 14 io6 DISCOVERY REPORTS Leucothoe spinicarpa (Abildg.). Pfeffer, 1888, p. 128, pi. ii, fig. 4 (antarctica). Chevreux, 1913, p. 108. Barnard, 1916, p. 148. Chilton, 1923 (Rec. Atistr. Mm.), p. 88. Schellenberg, 1926, p. 308; 193 1, p. 92. Monod, 1926, p. 53, fig. 51. Barnard, 1930, p. 338. Occurrence: 1. St. 2. Ascension. 1 juv. 2-5 mm. from buoy. 2. St. 39. South Georgia. 1 6* 9 mm., 7 juv. 5-7 mm. 3. St. 42. South Georgia. i(Jn mm. 4. St. 51. Falklands. 6 <$$ 7-10 mm., 5 $$ (1 ovig.) 7-9 mm., 1 juv. 3 mm., from sponges. 5. St. 149. South Georgia. 3 <$<$ 11-14 mm., 2 $? (1 ovig.) 13 mm., from sponge. 6. St. 170. South Shetlands. 1 J20 mm., 1 $ 18 mm. 7. St. 175. South Shetlands. 1 $ 21 mm. 8. St. 190. Palmer Archipelago (90-130 m.). 3 5*6* 8, 15 and 20 mm. 9. St. WS 27. South Georgia. 1 $ 10 mm., 2 juv. 4*5-6 mm. 10. St. MS 71. South Georgia. 1 6* I0 mm - Remarks. The minute specimen from Ascension has the postero-inferior angle of pleon segment 3 quadrate, and two small but definite denticles near the hinge on the palm of gnathopod 2 (cf. Chevreux and Fage, 1925, p. 123, fig. 119). The colour of no. 3 is given as "yellowish semitransparent ; penultimate segment of chela white, with terminal segment yellow; eyes pink"; and Note 145 for St. 190 gives it as " Ivory white with upper part of each thoracic and abdominal segment marbled with carnelian red (Ridgway, 7' R-O), coxopodite of each thoracic leg with 2 longitudinal patches of the same colour. Eyes brown". Distribution. Cosmopolitan. In the Antarctic regions recorded from McMurdo Sound, South Orkneys, South Georgia, Palmer Archipelago and Marguerite Bay, ' Gauss' winter station. Family SEBIDAE Walker, 1907, p. 37. Chevreux and Fage, 1925, p. 370. Genus Seba, Bate. Stebbing, 1906, pp. 162, 724. Walker, 1907, p. 37. Chilton, 1921 a, p. 56; 1924, p. 269. Schellenberg, 1926, p. 309; 1931, p. 83. Seba saundersii, Stebb. (Fig. 55). Stebbing, 1888, p. 783, pi. xlix. ? Schellenberg, 1926, p. 309, fig. 34 (dubia). Occurrence: St. 51. Falklands. 1 $ 3-5 mm., 3 $$ 2-5-3 mm - SEBIDAE 107 Remarks. These specimens are clearly identical with the Challenger specimen, although the minute denticulation on the telsonic apex appears to be quite absent. The c? has slightly heavier gnathopods 1 and 2, the hand and finger of gnathopod 1 in $ shaped as in antarctica, and strongly expanded 4th joints of peraeopods 3-5. Eyes not visible. Schellenberg's dubia appears very similar, especially as regards the telson, but the 2nd joint of peraeopods a. 6. c. 3 and 4 is less expanded. His descriptions of the 1st and Fig. 55. Seba saundersii, Stebb. a.Tel- 2nd side-plates (coxae I and II) would seem to be trans- son and uropod 3 of " d Fig. 59. Proboloides carinata (Schell.). a. Gnathopod 2 of immature (J. b. Gnathopod 2 of adult J. c. Gnathopod 1. d. Pleon segments 3-6. beaded on lower margin. Postero-inferior angle of pleon segment 3 quadrate. Gnatho- pod 1, 5th joint relatively longer, 6th relatively shorter, the latter parallel-sided, not distally expanded, palm oblique, setose. Gnathopod 2, notch on palm nearly semi- circular in immature °. 12-13 mm., 1 juv. 7 mm. Description. Integument on the pleon covered with minute pointed denticles, much smaller than in scabriculosus . Rostrum moderate, reaching to middle of 1st joint of antenna 1, deflexed, evenly curved. Head not narrowly produced behind eyes. Eyes visible as oval white patches, con- tiguous on top of head. Side-plates 1-4 rather deep, 1 expanded in front, 4 with posterior margin emarginate, lower mar- gin gently convex, i.e. not projecting very much lower than postero-inferior angle, the latter more narrowly rounded than in Stebbing's figure. Postero-inferior angle of pleon segment 3 broadly rounded. Telson quadrangular, slightly longer than Fig / ?8 \ ^ ono f ^ *»f ( Stebb -)- «• Gnatho- . pod 1. b. Gnathopod 2. c. Telson. d. Integumentary broad, apex truncate, straight or very sculpture from dorsum of pleon. slightly emarginate, angles rounded, with a seta near each. Antenna 1 reaching only a very short way beyond end of peduncle of antenna 2, 1st and 2nd joints subequal, 3rd much shorter, flagellum 15-jointed. Antenna 2, 5th joint a little, but distinctly, longer than 4th, flagellum mutilated. Gnathopod 1, 5th joint with process not nearly as narrow as in Stebbing's figure, extending half-way along hind margin of 6th, 6th ovoid, palm subequal to hind margin, defined by a small spine. Gnathopod 2, 5th joint with process narrow, extending not more than one-third length of hind margin of 6th, 6th elongate-ovoid, somewhat tapering distally, palm much shorter than hind margin and defined by a small spine. Peraeopods 1-5, cf. Stebbing's figures, 2nd joint of peraeopod 5 more broadly ex- 18-2 I4 o DISCOVERY REPORTS panded, subcircular, hind margin entire as in the figure on plate 7, not serrate as the figure of the whole animal on plate 6 seems to suggest. Remarks. It is but reasonable to assume that these specimens are the same as Stebbing's species, although the 5th joint of gnathopod 1 and the antennae are not exactly as Stebbing described them. It would seem that the antennae vary somewhat in relative lengths, though Stebbing even toyed with the idea of a new genus because the antennae in vallentini differed in length from those of the typical species Monoadopsis longicornis. The present specimens in this respect agree with those of Monocalodes. Distribution. Falkland Islands, low water. Genus Oediceroides, Stebb. Stebbing, 1906, p. 267. Chevreux, 191 1, p. 403. Schellenberg, 1926 b, p. 226; 1931, p. 139. Barnard, 1930, p. 366. Oediceroides calmani, Wlkr. Walker, 1907, p. 22, pi. vi, fig. 12. Strauss, 1909, p. 6, etc., pi. ii, figs. 6-8 (structure of eye). Chevreux, 191 1, p. 403, figs. 1, 2 (lahillei). Barnard, 1930, p. 366. Occurrence: 1. St. 45. South Georgia. 1 $ 17 mm. 2. St. 145. South Georgia. 2 $? 14-5 and 22 mm. 3. St. 159. South Georgia. 2 ?? 18-19 mm. 4. St. 167. South Orkneys. 1 <$, 1 $ 21 mm. 5. St. 180. Palmer Archipelago (160-330 m.). 5 ?? 12-20 mm. 6. St. 181. Palmer Archipelago. 2 <$<$ 16 and 18 mm., 8 ?$ (3 ovig.) 16-24 mm., 3 immat. 12-14 mm. 7. St. 182. Palmer Archipelago. 1 $ 17 mm., 1 ? 14 mm. 8. St. 190. Palmer Archipelago (315 m.). 2 ovig. ?? 21 mm. 9. St. WS 25. South Georgia. 1 $ 16 mm. 10. St. WS 33. South Georgia. 1 $ 19 mm., 1 juv. 10 mm. 11. St. MS 66. South Georgia. 1 $ 19 mm. 12. St. MS 67. South Georgia. 1 (J 12 mm. 13. St. MS 71. South Georgia. 2 $? 11 and 13 mm., 2 juv. 7-8 mm. Remarks. The eyes are much more gibbous and prominent than in Chevreux's figure. The two ?? from St. 145 are pale biscuit-colour, with numerous reddish specks, visible chiefly on head, side-plates 1 and 2, and on the pleon. The colour of the <$ from St. 45 is given as " all body segments closely covered with small maroon chromatophores, appendages pale, eye black". It would seem that lahillei is synonymous, showing an extreme development of the dorsal "wrinkling", which is somewhat variable, as is seen in the present material, and as was remarked upon by Chevreux in 1913 in comparing his specimens of calmani with Walker's original description. See also Schellenberg, 1931, p. 140. Distribution. Ross Sea, 100 fathoms and 256-379 m. ; Marguerite Bay, 200-254 m. ; South Sandwich Group, 30-50 fathoms. OEDICEROTIDAE 141 Oediceroides macrodactylus, Schell. (Fig. 79). Schellenberg, 193 1, p. 140, fig. 74. Occurrence: 1. St. 42. South Georgia. 3 ?$ 9-1 1 mm. 2. St. 45. South Georgia. 1 £ 11 mm., 8 $$ 10-15 mm. 3. St. 123. South Georgia. 30 $$ 9-13 mm. 4. St. 144. South Georgia. 15 $? 8-12 mm. 5. St. 148. South Georgia. 4??n-i2mm. 6. St. 149. South Georgia. 1 $ 10 mm., 3 $$ u-13 mm. 7. St. 195. South Shetlands. 4 33, 5 ?? 8-10 mm. Description. Integument minutely shagreened and pubescent. Head, peraeon and pleon dorsally rounded. Rostrum gibbous, de- flexed, extending to end of 1st joint of antenna 1. Antero-lateral angle of head subacute (as in Par- oediceroslynceus, Sars, 1895, pi. ciii). Eyesapparent- ly well developed, with glistening lenses, but quite white. Side-plate 1 strongly expanded and pro- duced forwards below, 4 moderately excavate on hind margin. Telson subquadrate, distally slightly emarginate. Antenna 1, 2nd joint nearly as long as 1st. Gnathopod 1, 5th joint broadly lobed below, posteriorly rounded, anterior angle subquadrate. Gnathopod 2, 5th joint produced downwards in the shape of an oblique oblong or plough-share, somewhat similar to that of calmani (see Chevreux, 1913, fig. 30 A), and quite unlike the rounded lobe in rostratns or Cinderella. Remarks. The characteristic features of this species are the even dorsal profile, the shape of the 5th joints in gnathopods 1 and 2, and the lack of coloured eye-pigment. The rostrum is not more gibbous than in newnesi or calmani. The colour of no. 2 is given as "anterior half of body orange-red, remainder and appendages pale yellow, eyes red". Genus Methalimedon, Schell. Schellenberg, 1931, p. 150. Methalimedon nordenskjoldi, Schell. (Fig. 80). Schellenberg, 1931, p. 150, fig. 79. Occurrence: 1. St. 27. South Georgia, iovig. $6 mm. 2. St. 140. South Georgia. 2 ?$ (1 ovig.) 6 mm. 3. St. WS 33. South Georgia. 4 ??7mm. Remarks. This form is very close to Parhali- medon turqueti, Chevr., 1906, with which I at first identified the above specimens . They agree, however, with Schellenberg's description. Fig. 79. Oediceroides macrodactylus, Schell. a. Gnathopod 1. b. Gnathopod 2. Fig. 80. Methalimedon nordenskjoldi, Schell. a. Head. b. Telson. 142 DISCOVERY REPORTS Family LILJEBORGIIDAE Stebbing, 1906, p. 229. Genus Liljeborgia, Bate. Stebbing, 1906, p. 230; 1910, p. 588. Schellenberg, 1925, p. 144; 193 1, p. 128. This genus is in an unsatisfactory state. I have not seen Walker's discussion of the variability of the dorsal denticles (Tr. Liverp. Biol. Soc. xxm, 102, 1907). The shape of the epistome may prove to be a useful specific character, but up to the present it has not been incorporated in descriptions, though it is more or less clearly indicated in the enlarged drawings of the head in Sars (1895). This defect should be remedied as soon as possible by some student having access to northern and Australasian material. The South African specimen, identified by Stebbing as dubia, another resembling it in dorsal denticulation, and the specimen referred by me to proximo. (1916, p. 167) are in too poor a condition to give any trustworthy evidence on this point. It would seem also that the adult S has features of considerable specific importance, namely, gnathopod 2 and peraeopod 5 (cf. Barnard, 1930, p. 365). Very few fully adult SS seem to have been noticed. Liljeborgia kinahani (Bate) (Fig. 81). Sars, 1895, p. 532, pi. clxxxviii, fig. 1. Stebbing, 1906, p. 233. var. capensis n. Occurrence: St. 90. South Africa. 1 $ 10 mm., 1 ovig. $ 8 mm. var. georgensis n. Occurrence: St. 145. South Georgia. 1 ovig. ? 15 mm. var. falklandica n. Fig. 81. Liljeborgia kinahani (Bate). Profile of r\ o^ 1^ 11 1 j < epistome and upper lipof :a. War. capensis n. b. Var. Occurrence: St. 57. ralklands. 1 ^iimm. r . "1 *;„_ ,. r 1 ... georgensis n. c. Var. falklandica n. a. 2nd joint ot Remarks. These specimens all agree with peraeopod 5 (j) of var. falklandica. Sars' figure and the descriptions of the northern kinahani as regards the tridentate pleon segments 1 and 2, and the single short decumbent tooth on both pleon segments 4 and 5. The fingers of gnathopods 1 and 2, however, have 7 and 17 serrations respectively; thus considerably more than in typical kinahani. The eyes are well developed, large (as in Chevreux's figure of consanguinea, 1913, fig. 25), black. Epistome with the projecting keel triangular with an obtuse point in var. capensis, rounded subtriangular in var. georgensis, and oblong in var . falklandica . Postero-inferior angles of side-plates 5 and 6 quadrate or slightly subacute, not toothed as in mixta Schell. Hind margin of 2nd joint of peraeopod 5 with strong, deeply-indented serrations. LILJEBORGIIDAE 143 The difference between the three varieties lies in the epistome. It is admittedly very slight, but it exists, and on the material at hand from three different localities it is im- possible to say whether it is a constant or variable feature. In the following species the epistome, while varying slightly as do all parts of an animal when several examples are studied, yet preserves its essential characteristic shape. The institution of three varietal names will perhaps be excused for this reason. All the specimens, especially those from the more southerly localities, are larger than typical kinahani. If the dorsal denticles should prove to be variable it may be possible to include Chevreux's specimens under one or other of the above varieties, with which they conform in having large black eyes. For this latter reason I do not agree with Chevreux in assigning them to consanguinea, Stebb. Schellenberg has named these specimens chevrenxi (193 1, p. 128), and has also described five more species (pp. 129-136), without, however, making reference to the epistome. Liljeborgia longicornis (Schell.) (Fig. 82). Schellenberg, 1931, p. 137, fig. 73. Occurrence: 1. St. 27. South Georgia. 1 ovig. $ 10-5 mm. 2. St. 51. Falkland's. 1 $ 18 mm., 3 $? 10, 11 and 17 mm., 1 juv. 5 mm. 3. St. 144. South Georgia. 2 ovig. $$ 13-5 and 15 mm. 4. St. 159. South Georgia. 1 mutilated 15 mm. 5. St. 160. Shag Rocks. 1 and pitted sculpturing. 11 i-i ■ -, 1 • b. Portion of margin of 2nd segment 4 is more rounded, not as high even in n segment 3. c. Telson. and without the distinct triangular apex of tridentata. Epistome and upper lip much less gibbous than in the other species. Antenna 1 with i-jointed accessory flagellum. Fig. 101. Oradarea edentata, n.sp. a. Side-plate 1 with integumentary sculpture further enlarged. 168 DISCOVERY REPORTS Gnathopod i, 6th joint slender and cylindrical, approaching in shape, though not in length, the 6th joint of gnathopod 2. Peraeopods 3-5, 2nd joint with hind margin obscurely serrulate. Colour (as preserved) orange-brown, formed by numerous close-set stellate chromatophores ; eyes darker, reddish-brown. Remarks. It is probable that some of Chevreux' specimens from Petermann Island belong to this species. He refers to an ovigerous $, 6 mm. in length, without any dorsal teeth. He also mentions that some examples had a punctuated coloration, with brick- red eyes. The respective localities are not very far distant from one another. Family PLEUSTIDAE Stebbing, 1906, pp. 309, 728. The only Pleustid hitherto recorded from the southern hemisphere is Mesopleustes abyssorum (Stebb.) from Marion Island. Genus Austropleustes, Brnrd. Barnard, 1931, p. 428. Rostrum short. Side-plates moderate. Antennae slender, elongate. Upper lip incised. Outer lobes of lower lip widely separated. Mandible with molar feeble, conical, setulose; 3rd joint of palp shorter than 2nd. Palp of maxilliped with 3rd joint apically produced as in Stenopleustes (Fig. 103/). Gnathopods 1 and 2 subchelate, rather slender. Dactyls of peraeopods 1-5 with a denticle at base of unguis. Uropod 3 with peduncle apically produced on lower margin to support the rami, of which inner is much longer than outer, and triquetral in cross-section. Telson more or less boat-shaped, apically more or less notched. Genotype: A. cuspidatus n.sp. Remarks. The mouth-parts of the species described below are in agreement with those of Stenopleustes, except the molar of the mandible, which is rather feeble but not as feeble as in Pleustes and Neopleustes. This feature, in conjunction with the peduncle of uropod 3, warrants generic separation. The structure of the peduncle of uropod 3 may be compared with that of Oradarea described above, or that of Liouvillea. Austropleustes cuspidatus, Brnrd. (Fig. 102). Barnard, 1931, p. 428. Occurrence: St. 170. South Shetlands. 2 $$ (1 ovig.) 15 mm. Description. Integument (as preserved) moderately firm, with minute, transversely elongate granules, chiefly on the hinder half of body. Rostrum extending to just half- way along 1st joint of antenna 1. Eyes large, round-oval, yellowish. Head and peraeon segments 1-5 feebly carinate. Peraeon segments 6 and 7 each with a pair of dorsal cusps; segment 7 with a lateral tooth on posterior margin, nearer the side-plate than the dorsal cusps. Side-plates, as in S. nodifer (Sars, 1895, pi. cxxv, fig. 2). Pleon segments PLEUSTIDAE 169 1-3 carinate, the carina on segments 1 and 2 raised posteriorly into a strong pointed tooth, on segment 3 rounded. Postero-inferior angle of segment 3 shortly pointed. Telson boat-shaped, apex slightly incised, a small subterminal notch on lateral margin. Both antennae elongate, slender, flagella multiarticulate. Mouth-parts as in S. malmgreni (Sars, 1895, pi. cxxv, fig. 1), except that the mandible has a rather feeble conical molar, minutely setulose at apex; cutting edge with about 10 teeth, secondary cutting plate in left mandible with about eight teeth, in right mandible bidentate. Gnathopods 1 and 2, 2nd joint shallowly channelled in front, outer margin slightly lobed at distal end, 4th with a short sharp spine at lower distal angle, 5th and 6th sub- equal, rather elongate, both setose along lower margins, 5th with two rather stronger spine-setae distally, 6th cylindrical, palm oblique, not defined except by three stout submarginal spines, finger overlapping palm. Fig. 102. Austropleustes cuspidatus, Brnrd. a. Gnathopod 1. b. Peraeon segments 6 and 7, and pleon seg- ments 1-4. c, d. Dorsal and lateral views of telson. e. Dorsal view of uropod 3 (inner ramus missing). Peraeopods 1 and 2, 5th and 6th joints rather strongly spinose on hind margin, dactyls with a small denticle at base of unguis. Peraeopods 3-5, 2nd joint ovately ex- panded, hind margin shallowly notched, 5th and 6th joints rather strongly spinose on anterior margins, dactyls with denticle as in peraeopods 1 and 2. Uropods 1 and 2, peduncle longer than rami in uropod 1, shorter than the rami in uropod 2. Uropod 3, peduncle with upper margin keeled and ending in a short tooth, produced below into a channelled process for the reception of the inner ramus, which is lost in both specimens, but is presumably elongate. Remarks. Distinguished from all other Pleustids by the dorsal armature. Austropleustes simplex, n.sp. (Fig. 103). Occurrence: St. 123. South Georgia. One specimen 8 mm. Description. Integument (as preserved) not firm, minutely and regularly shagreened. Rostrum extending scarcely to half-way along 1st joint of antenna 1. Eyes rather large, reniform, yellowish. Postantennal angle of head shortly produced in an acute point. 170 DISCOVERY REPORTS Peraeon and pleon without any carinae or processes. Side-plate i widened below, feebly serrulate ; side-plates 5 and 6 more evenly bilobed than in cuspidatus or Stenopleustes nodifer. Postero-inferior angle of pleon segment 3 quadrate, the hind margin nearly straight, and obscurely crenulate. Telson not so strongly boat-shaped as in cuspidatus, apex more deeply incised, each lobe with 3-4 denticles, with fine setules in the notches. Mouth-parts as in S. malmgreni (Sars, pi. cxxv, fig. 1) except that the molar agrees with that of cuspidatus (supra) in being rather feeble and conical. Gnathopods 1 and 2 in general like those of cuspidatus, but 5th and 6th joints not so elongate. Peraeopods 1-5 all have the denticle on the dactyl. Hind margin of 2nd joints of peraeopods 3-5 serrate. Fig. 103. Austropleustes simplex, n.sp. a. Head. b. Side-plate 1 and gnathopod 1. c. Side-plate 4. d. Pleon segment 3. e. Telson. /. Maxilliped, with 3rd and 4th palpal joints further enlarged. Uropod 3, peduncle apically produced as in cuspidatus, inner ramus twice as long as outer, triquetral in cross-section, margins spinulose. Remarks. Although so unlike the preceding species in having no dorsal armature, this species agrees with the former in the mouth-parts, uropod 3, and the dactyls of peraeopods 3-5. Family PARAMPHITHOIDAE Stebhing, 1906, p. 320. Barnard, 1930, p. 372. Genus Epimeria, Costa Stebbing, 1906, p. 321. Barnard, 191 6, p. 170; 1930, p. 372. PARAMPHITHOIDAE i7i This genus contains a number of species which can be separated into two more or less distinct groups, characterized by the tendency of the integumentary projections to be on the one hand spiniform and on the other hand tuberculiform. Admittedly there is no hard and fast division, but taking the Antarctic examples one would at first sight be inclined to doubt whether macrodonta and robusta belonged to the same genus. In the Antarctic fauna the macrodonta group causes no trouble. But in what may be termed the inermis-robusta group we find a number of very closely allied forms which illustrate in varying degrees the tendency among so many polar forms to develop integumentary processes. Fig. 104. 2nd and 3rd joints of peraeopod 3 of Epimeria viewed obliquely from behind: a. inermis, Wlkr. b. acanthurus, Schell. c. intermedia, Schell. d. puncticulata, Brnrd. e. excisipes, n.sp. (In d the faintly dotted line indicates the bottom of the channel formed by the inner and outer keels.) These are mostly large forms and hence are amenable to a somewhat closer scrutiny than many smaller forms. Thus in the study of the Discovery material I have become aware of one feature which would seem to be of considerable value in diagnosing the species. Unfortunately the three species in the Terra Nova collection were so clearly differentiated on the more obvious features that the detail to which I am here drawing attention did not obtrude itself. That, however, is of little consequence as two of those species occur in the Discovery collection, and it is only robusta that I am not able to include in the following comparison. The 2nd joints of peraeopods 3-5 have participated to a greater or lesser degree in the general induration of the integument in these forms, for the purpose of closing the gap between the 4th and 5th side-plates and the pleura of the pleon segments when the animal is curled up. They thus become available for the development of rib-like strengthening keels, marginal flanges and spiniform projections. I7 2 DISCOVERY REPORTS The simplest development is seen in the northern cornigera, where the hind margin of the 2nd joint in peraeopods 3 and 4 is channelled, the channel being bounded by a keel or flange on the outer and inner sides. These keels diverge right from the base of the joint, and continue separate to the end, where the outer one is expanded into a lobe. On peraeopod 4 the inner keel is slightly expanded. On peraeopod 5 it is always the outer keel which is variously expanded, and we need not consider this peraeopod any further. All three peraeopods have a longitudinal keel in the middle of the outer surface of the 2nd joint, and the 3rd joint also possesses an outer and inner flange on the hind margin for the reception of the 4th joint when the limb is flexed. In the Antarctic forms we find several modifications of the simple channel of cornigera. In explanation of the figures here given (Fig. 104) of all the species in the present collection, it will suffice to point out how important it is in descriptions to distinguish the point of divergence of the outer and inner keels, which keel is expanded, and the course of the lateral longitudinal keel. Epimeria macrodonta, Wlkr. (Fig. 105). Walker, 1907, p. 24, pi. viii, fig. 14. Chevreux, 1913, p. 148 and p. 149, figs. 41-43 (similis). Schellenberg, 1926, p. 343. Barnard, 1930, p. 372. forma macrodonta, Wlkr. Occurrence: St. 181. Palmer Archipelago. 1 juv. 10 mm. forma similis, Chevr. Occurrence: 1. St. 170. South Shetlands. 19 SS 12-22 mm., 16 $$ 15-34 mm -> 8 ovi g- ?? 2 §- 32 mm., 2 ?$ with embryos 33 mm. 2. St. 175. South Shetlands. 2 c?c? 12 and 30 mm. 3. St. 181. Palmer Archipelago. 1 ? $ 14 mm. 4. St. 182. Palmer Archipelago. 1 £ 18 mm., 1 juv. 6-5 mm. Fig. 105. Epimeria macrodonla, Wlkr. Photograph taken on board (St. 175). PARAMPHITHOIDAE 173 Remarks. The large $ (no. 2) is larger than any other known a, and the spiny arma- ture in both specimens of no. 2 is unusually well developed. Peraeon segment 1 has a medio-dorsal subacute tooth, and a dorso-lateral short pointed tubercle. Segment 2 is unarmed, and dorsally is only half the length of segment 1. The dorsal processes on peraeon segment 3 to pleon segment 3 are high, shaped more as in similis than macro- donta in the larger o* , vice versa in the smaller $ ; in the former especially those on peraeon segment 7 and pleon segments 1 and 2. The processes on segment 7 and pleon segment 2 in the larger $ (broken off in the smaller) are sub-bifid, the posterior point on pleon segment 2 being very narrow and acute. Side-plate 2 scarcely wider than 1. The horizontal tooth in middle of side-plate 4, which is usually short, or as in most specimens in no. 1 nearly obsolete, is here very strong, projecting laterally almost as much as does the tooth on side-plate 5. No further evidence is required to demonstrate that macrodonta and similis are forms of the same species. The extreme forms are easily distinguished, but intergradations may occur. Many of the specimens of no. 1 , especially the smaller ones, have the dorsal processes approximating to the slender macrodonta type. The inter- antennal area bears two short acute median tubercles, one just below the bases of 1st antennae, the other just above the base of the epistome. These tubercles are not mentioned by other authors, and were not looked for in the Terra Nova specimens. The colour of the no. 1 specimens is given as: "Thoracic and abdominal segments white blotched and striped with yellowish buff, antennae, antennules, distal segments of three posterior legs, and uropods suffused with same colour. Eyes shining salmon pink ". Note 128 for St. 175, and Note 141 for St. 181 give the colour as: "Carapace and abdomen golden yellow, with numerous spots and streaks of bright red. Eyes salmon red", and "Pale creamy buff with faint chestnut mottling. Eyes pink", respectively. Distribution. McMurdo Sound; Coats Land; Graham Land; South Shetlands; ' Gauss' winter station. Epimeria inermis, Wlkr. (Fig. 104 a). Walker, 1903, p. 54, pi. x, fig. 69. Barnard, 1930, p. 374, fig. 40 b. Occurrence: 1. St. 170. South Shetlands. 6 ?$ 10-23 mm -> 5 oy ig- ?? 20-28 mm., 1 juv. 6 mm. 2. St. 175. South Shetlands. 1 £ 13-5 mm., 2 ?$ 19 and 21 mm. Remarks. These specimens confirm the remarks made on the Terra Nova specimens. The description of the 2nd joint of peraeopods 3 and 4 can be improved, viz. hind margin forming in basal third a rounded triangular tooth or projection, then diverging into the outer and inner keels, neither of which is expanded or lobed distally, longi- tudinal keel distinct from base to apex. One inter-antennal tubercle below bases of 1st antennae. The colour of no. 1 is given as: " Cream-coloured, closely dotted all over with terra- cotta, 5th and 8th [sic] thoracic segments much darker than rest. Antennae, antennules and last five thoracic legs narrowly banded with same colour. Eyes salmon pink ". When 174 DISCOVERY REPORTS this and the following species (excisipes) were caught in the same haul, they were dis- tinguished in the field and separate colour notes were made. Distribution. Cape Adare, 28 fathoms; McMurdo Sound, 256-379 m.; west of Falkland Islands, 229 m. Epimeria excisipes, n.sp. (Figs. 104 £, 106, 107). Occurrence: 1. St. 27. South Georgia. 1 $ 30 mm. 2. St. 42. South Georgia. 1 6 ?? 22-27 mm -> 5 ov 'g- ?? 34" 39 mm., 1 $ with embryos 29 mm. 10. St. 175. South Shetlands. 2 S3 15-16 mm., 5 ?$ 14-38 mm. n. St. 190. Palmer Archipelago (315 m.). 1 S 21 mm. 12. St. 195. South Shetlands. 1 3 21 mm., 1 $ 15 mm. 13. St. WS 33. South Georgia. 1 ovig. $ 31 mm. Fig. 106. Epimeria excisipes, n.sp. Photograph taken on board (St. 175). Fig. 107. Epimeria excisipes, n.sp. Side-plates 4-7 and 2nd joints of peraeopods 3-5. Description. Integument, rostrum, peraeon and pleon as in inermis Wlkr., but side- plates 4-6 thicker and more strongly gibbose. Side-plate 4 concave on lower hind margin, lower margin straight or slightly concave, antero- and postero-inferior angles quadrate, almost sharp in some specimens. Side-plate 6 pointed below (rounded in inermis). The lower margins of the peraeon segments are not at all tuberculate or gibbose. Some specimens are almost foveolate on the pleura of pleon segments 1-3. Peraeopods 3-5, 2nd joints closely resembling those of robusta Brnrd., but that of peraeopod 5 distinctively expanded in its proximal two-thirds into a broad lamina, bounded below by an acute re-entrant angle. In some of the smaller S3 this re-entrant angle or excision on all three peraeopods is more a right angle than an acute angle. PARAMPHITHOIDAE I75 Uropod 2, outer ramus a little over half length of inner. One inter-antennal tubercle. The embryos (no. 9) are 5-5 mm. in length, and the 2nd joints of peraeopods 3-5 are of the inermis or tuber cidata shape. The back is feebly carinate. Remarks. Although closely related to inermis and robusta, this species is easily dis- tinguished by the diagnostic characters here described and figured. Though size is not distinctive, it seems to be a larger species than inermis. When the animal is curled up, the manner in which the overlapping 2nd joints of peraeopods 3-5 fill in and protect the space between the 4th side-plate and the pleura of the pleon segments is very neat. The embryos of no. 9, and the young individuals of no. 4 are interesting as showing the progressive enlargement of the basal tooth on the 2nd joints of peraeopods 3 and 4, the shifting of the point of divergence of the outer and inner keels further towards the apex of the joint, the expansion on the same joint of peraeopod 5 and its extension distal- wards. As regards the shape of these joints, excisipes when first hatched resembles inermis but diverges more and more as it grows. The 4th side-plate is distinctive right from the earliest stage. The colour of nos. 1, 2 and 9 respectively are given as: "Rose-red with red eyes", "heavily mottled with red on a creamy ground. Eyes bright pink", and "Variously mottled with milk-white on a bright red or crimson background. Some specimens mainly white, others mainly red. Eyes shining red". Note 131 for St. 175 says: "Thorax and abdomen heavily blotched and mottled with deep carmine on a pure white ground, the amount of carmine pigment varying greatly in different specimens. Last three thoracic legs dotted with carmine. Eyes shining salmon pink". This species is very likely a synonym of E. georgiana, Schell. 1931, p. 160. Epimeria puncticulata, Brnrd. (Fig. 104 d). Barnard, 1930, p. 376, fig. 42. Occurrence: 1. St. 45. South Georgia. 1 $ 13 mm. 2. St. 123. South Georgia. 3 $? 11-13 mm. 3. St. 140. South Georgia. 8 $$ 10-13 mm - 4. St. 148. South Georgia. 1 <$ 10-5 mm. 5. St. WS33. South Georgia. 1 $ 7 mm. 6. St. MS 71. South Georgia. 1 juv. 5-5 mm. Remarks. The 7th peraeon segment ends in a short medio-dorsal point, the keels on pleon segments 1 and 2 end in slightly more prominent points, and the triangular pro- jection on segment 4 is more sharply pointed than in the Terra Nova specimens. The hind margin of 2nd joint of peraeopod 5 is usually slightly indented distally, but the lobe has a small point at the postero-inferior corner. The figure here given of the 2nd joint of peraeopod 3 shows the point of divergence of the outer and inner keels right at the base, the strong sinuous expansion of the outer keel, ending in a sharp point, into which the lateral longitudinal keel does not enter, and the feeble expansion of the inner keel, which ends below in a small subacute lobe. In a true external side-view the inner keel is scarcely visible below the concavity of the outer 1 7 6 DISCOVERY REPORTS keel (cf. fig. 42, 1930). In peraeopod 4 the inner keel is completely concealed in external view, and an apical lobe is scarcely developed. One inter-antennal tubercle. The colour of no. 1 is given as follows: "Pale yellow. Each of first 7 segments with a transverse pale brown band dorsally along both anterior and posterior margins. Large side-plate of 4th segment largely red-brown. Posterior segments yellow mottled with brown. Caudal appendages and legs pale yellow. Eyes red". Distribution. McMurdo Sound, 92-175 m. Epimeria acanthurus, Schell. (Figs. 104 b, 108, and Plate I, fig. 2). Schellenberg, 1931, p. 162, fig. 85, and pi. i, fig. g. Occurrence : 1 . St. WS 81. Falklands. 1 ovig. $ 22 mm. 2. St. WS 85. Falklands. 1 $ 11-5 mm. 3. St. WS 86. Falklands. 1 ovig. $ 21 mm. b. c d Fig. 108. Epimeria acanthurus, Schell. a. Dorsal profile of peraeon segments 6 and 7 and pleon segments 1-4. b, c, d. 2nd (and 3rd) joints of peraeopods 3-5. Description. Like puncticulata, Brnrd., but peraeon segments 5 and 6 slightly keeled and ending posteriorly in a short point. Peraeon segment 7 and pleon segments 1-3 strongly keeled, the keels beginning near bases of segments, slightly indented in middle of dorsal profile, and ending in prominent subacute apices. Pleon segment 4 with sharp-pointed upstanding triangular process. A series of dorso-lateral tubercular processes on peraeon segment 7 to pleon segment 3, faint on peraeon segment 7 (some- times also one on segment 6) and on pleon segments 2 and 3 , consisting of a short ridge or keel near base of segment and a conical tubercle on hind margin. Peraeopods 3 and 4, 2nd joint with the point of divergence of the outer and inner keels distal to the rounded basal lobe, inner keel not expanded, lateral longitudinal keel confluent in distal third with the outer keel and forming the subacute apex of the distal lobe, which does not quite extend to apex of 3rd joint. Peraeopod 5, 2nd joint similar PARAMPHITHOIDAE 177 to that of puncticulata but distal hind margin lobe ending in a subacute point, to which the lateral longitudinal keel runs out. One inter-antennal tubercle. Remarks. There is very strong temptation to regard this form as a more strongly tuberculate variety of puncticulata, especially as a somewhat similar colour pattern is found in both. The differences in the dorsal armature, however, are considerable; puncticulata is much broader across the middle of the peraeon than acanthurus; and finally the structure of the 2nd joints of peraeopods 3 and 4 is decisive. Schellenberg (193 1, p. 162) has proposed the genus Metepimeria for this species. The distinctly striped coloration of no. 1 offers an interesting contrast with the blotched coloration of nos. 2 and 3. The type (no. 1) still exhibits the pairs of faint salmon bands on peraeon segment 1 to pleon segment 4 ; the pleon segments have an additional band right at the base; side-plates 4 and 5 show two bands, and side-plate 6 one band, being the direct continuation of those on the peraeon segments. Note WS 12 for St. WS 86 says : " Colour and markings . . . with a more universal distribution of red pigment. . . [than in Note WS 9, which is the coloured sketch here reproduced] i. Red pigment extends to posterior border of head. ii. Coxopodites of 2nd, 3rd and 4th thoracic legs are pigmented, of the 4th completely, iii. Terga of the 6th and 7th free thoracic segments and the coxopodites of their appendages are fully pigmented, iv. Terga of all abdominal segments completely pigmented, v. Basipodites of the last three peraeopods bear colour at base of their hinder margins". Epimeria intermedia, Schell. (Figs. 104 c, 109). Schellenberg, 1931, p. 161, fig. 84, and pi. i, fig./. Occurrence: 1. St. 39. South Georgia. 1 ? 15 mm. 2. St. 140. South Georgia. 2 $? 10 and 12 mm. 3. St. 142. South Georgia. 1 juv. 5-5 mm. b a Fig. 109. Epimeria intermedia, Schell a. General view b. Cross-section of peraeon segment 2. Description. Integument strongly punctate. Rostrum as long as rest of head or even a little longer (no. 2). Two inter-antennal tubercles Peraeon segments 1-7 dorsally carinate, the carinae becoming successively stronger and more imbricate posteriorly; dorso-laterally a slight ridge projecting horizontally and giving a very D V 23 178 DISCOVERY REPORTS characteristic appearance; posterior margins of segments 5-7 faintly beaded between the dorso-lateral and medio-dorsal keels. Lower margins of segments feebly nodulose (obsolete in no. 1). Side-plate 4 deeper than long, antero-inferior angle rounded, postero-inferior angle quadrate; side-plates 5 and 6 nodose. Pleon segments 1-4 dorsally carinate, like the peraeon with a dorso-lateral ridge, and laterally somewhat irregularly and feebly nodulose ; carina on segment 4 acutely triangular ; segment 5 very short; segment 6 with a medio-dorsal upstanding triangular tooth, and the lateral margins produced backwards in acute lobes. Postero-inferior angle of pleon segment 3 produced in an acute upcurved hook; no angular projections on lateral margins above the postero-inferior angles. Peraeopods 3 and 4, 2nd joints with an uncinate process on basal hind margin, beyond which the outer and inner keels diverge, the former expanded and ending in a slightly produced quadrate lobe, the latter scarcely expanded, lateral longitudinal keel running to the lower margin of lobe of outer keel. Peraeopod 5, 2nd joint with hind margin strongly expanded, the distal one-third semicircularly excised. Uropod 2, outer ramus two-thirds length of inner. Remarks. The larger specimen, no. 1, is less nodose than the two smaller ones (no. 2) and but for the latter several of the less noticeable features would have been overlooked or ignored. Walker, 1907, p. 26. Barnard, 1930, p. 377. Genus Epimeriella, Wlkr. Epimeriella macronyx, Wlkr. (Plate I, fig. 3). Walker, 1907, p. 26, pi. ix, fig. 15. Schellenberg, 1926, p. 344. Barnard, 1930, p. 378. Occurrence: St. 162. South Orkneys. 1 $ 21 mm. Remarks. Side-plates 1-3 narrowly rounded or subacute below. The remarks on the Terra Nova specimens apply here also. Sixth joint of peraeopods 3 and 4 equal to the 2nd~4th joints together; dactyl two-thirds length of 6th joint. (The 6th joint is drawn a little too short in the coloured figure here reproduced.) Distribution. McMurdo Sound, 5-10 fathoms and 0-350 m.; 'Gauss' winter station, 385 m. Epimeriella walked, Brnrd. (Fig. no). Barnard, 1930, p. 380, figs. 40 c and 44. Occurrence: 1. St. 170. South Shetlands. 3 S3 "-13 mm., 25 $$ 14-18 mm. 2. St. 182. Palmer Archipelago. 1 ? 17 mm. Remarks. None of the specimens are fully mature, but they agree with the original description except as regards gnathopods 1 and 2. The 6th joint has a distinct rounded palm as in the embryo figured in fig. 44 c (1930), and is finely pectinate as in scabrosa PARAMPHITHOIDAE 179 (1930, fig. 43 c); the dactyl bears a series of slender spines separated by short spaces. The postero-inferior angles of the 2nd joints of peraeopods 3 and 4 are more rounded- quadrate, especially in peraeopod 3. There is one inter-antennal tubercle. Specimen no. 2 has pleon segment 3 terminating in a more prominent blunt process, the posterior prominence on segment 4 is higher and symmetrically rounded, and the 6. c. d Fig. no. Epimeriellawalkeri, Brnrd. a. Gnathopod 1. b. Pleon segments 1-6. c,d,e. 2nd (and 3rd) joints of peraeopods 3-5. (b-e are from the specimen from St. 182.) postero-inferior angles of the 2nd joints of peraeopods 3 and 4 are quite rounded; but in other respects it resembles the other specimens. This specimen is recorded as being "pure white with pink eyes". Distribution. McMurdo Sound, 256-379 m. Genus Parepimeria, Chevr. Chevreux, 1913, p. 158. Schellenberg, 1931, p. 164. All the present specimens have a normal 4-jointed palp in the maxilliped, and the original generic definition must therefore be altered. The 4th joint is often difficult to see on account of the thick brush of setae on the 3rd joint. Parepimeria crenulata, Chevr. Chevreux, 1913, p. 158, figs. 47-49. Typical form Occurrence: 1. St. 42. South Georgia. 1 1 $ both 47 mm. 5. St. 186. Palmer Archipelago. 1 $ 40 mm. 6. St. 190. Palmer Archipelago (90-130 m.). 3 immat. £$ 26-28 mm., 2 immat. $? 25-26 mm. 7. St. 190. Palmer Archipelago (315 m.). 1 immat. $ 26 mm. 8. St. 195. South Shetlands. 1 ovig. $ 50 mm. Remarks. As preserved the eye is dark brown, surrounded by a paler ring. There is only one actually ovigerous $; the largest ?? from St. 167 have the brood pouches fully developed and extended but empty, and are thus either spent or have lost their eggs during capture and preservation. The dates of these captures were in February and March. The Terra Nova fully-developed $? were caught in January and February. i 9 o DISCOVERY REPORTS Colour notes made from fresh specimens are as follows: Note 127 for St. 170: "Ground colour of thorax and body ochraceous buff, darkest dorsally and palest laterally, with conspicuous red blotches and mottling. Between the eyes 4 red spots, 2 median and 1 pair lateral. Second and third [sic = 1st and 2nd] thoracic segments wholly red. Fourth to eighth [sic = 3rd-7th] segments faintly mottled with red, but with more conspicuous mottling on the coxal plates. First 3 abdominal segments blotched with red, with a specially dark patch mid-laterally on 1st and 2nd segments. Fig. 115. Eusiras perdentatus, Chevr. Photographs taken on board (Notes 127 and 146). Remaining abdominal segments and telson marked with red dorsally. Antennules suffused with red; antennae blotched with crimson. Mouth-parts and both gnathopods deep crimson, with a suffusion of the same colour on the coxal plates. The 5 thoracic legs milk-white, the first 2 red at the tips, the remainder heavily blotched with red. First 3 pleopods white, the remainder and uropods [sic = uropods 1-3] suffused with red. Eyes grey black". Note 146 for St. 190 (no. 6): "Creamy buff, mottled and marbled with bright scarlet. Thoracic legs with scarlet bands. Eyes dark brown". Distribution. Palmer Archipelago, 60-70 m. ; South Orkneys, 54 fathoms ; ' Gauss ' winter station, 385 m.; Ross Sea and McMurdo Sound, 329-547 m. EUSIRIDAE 191 Eusirus microps, Wlkr. Walker, 1907, p. 31, pi. xi, fig. 19. Barnard, 1930, p. 385, fig. 47 (references). Occurrence: 1. St. 116. Bouvet Island. 1 juv. 8-5 mm. 2. St. 202. South Shetlands. 1 ? 34 mm. Remarks. The eyes as preserved are black. The juvenile from St. 116 is interesting. Small as it is, there is no doubt that it belongs to this species. The eye is subcircular and the side-plates are characteristically shallow. The hands in both gnathopods are oval, though the anterior margin is slightly shorter than the anterior margin of the 5th joint. Only pleon segments 1 and 2 are dentate. In contrast to both the preceding species, this species seems to inhabit the upper layers, though maybe it ascends at night time, as both the present captures were made at night. From previous records it would seem to be a frequent food of penguins. Distribution. McMurdo Sound; Petermann Island; 'Gauss' winter station. Genus Eusiroides, Stebb. Stebbing, 1906, pp. 345, 729; 1910, p. 594. Pirlot, 1929 a, p. 10. Schellenberg, 1929 a, p. 282. For further reasons against Chilton's suggestion of sinking this genus in Bovallia, see under the latter genus (p. 196). One may refer here to the importance of examining the integumentary sculpture. The present specimens, and the South African ones referred to monoculoides (Barnard, 19 16, p. 174), exhibit a type of sculpture entirely different from that of Bovallia. Eusiroides georgianus, n.sp. (Fig. 116). Occurrence: 1. St. 141. South Georgia. 1 ovig. $15 mm. 2. St. 159. South Georgia. 1 ovig. $ 16 mm. 3. St. 170. South Shetlands. 3 $$ (2 ovig. 1 with embryos) 16-17 mm. 4. St. 175. South Shetlands. 1 $ 16 mm. 5. St. WS 25. South Georgia. 2 ?? 16 and 20 mm., 1 ovig. $ 20 mm. 6. St. MS 25. South Georgia. 1 c? 15 mm., 1 ovig. $ 18 mm. Types. 7. St. MS 71. South Georgia. 1 $ 20 mm. Description. Agreeing in almost every particular with Stebbing's original descrip- tion and figures of crassi. Whole peraeon and pleon dorsally rounded, without any sug- gestions of teeth. Postero-inferior angle of pleon segment 3 rather more produced than in Stebbing's figure, rounded, but with a tiny tooth and a rounded sinus. Side-plate 1 strongly widened below and produced forwards. Gnathopods 1 and 2, 6th joint more ovate, palm more oblique and longer than in Stebbing's figures of crassi, thus approximating to those of caesaris ; the palmar spines also like those of the latter species, not so stout as in crassi. 192 DISCOVERY REPORTS •:•'».:• ■:*;.':'■ Maxilla i, 3-4 setae on inner lobe. Maxilla 2, inner lobe broader than outer, without any submarginal oblique row of setae. Telson twice as long as basal width, cleft for just over half its length, the lobes tapering evenly to acute entire apices, one or two long upstanding simple setae on lateral margin at about two-thirds or three- quarters the length (absent in no. 5) . Under a high magnification the surface appears covered with very fine transverse lines. In the embryo from the brood-pouch the telson resembles that of the adult in shape and extent of the cleft. Integument very minutely shagreened, with scattered pits; under a high magnification by transmitted light very fine more or less parallel lines are visible as in the enlarged portion of the telson figured here. Eyes reniform, nearly contiguous dorsally. Remarks. It would be easy to regard this form as a variety of crassi, which was taken farther north off Monte Video in 600 fathoms ; or perhaps to regard the combination of a pleon segment 3 with only one notch, together with the palm of gnathopods as in crassi, as an argument for uniting the "triumvirate " caesaris,pompeii and crassi. Between a sinus and a serration there would seem to be but little difference ; yet there is a difference and it would not be quite correct terminologically to describe the sinus of pleon segment 3 in the. present specimens as a single serration (cf . the figure here given with Stebbing's figure of the pleon segment 3 in caesaris or pompeii, 1888, pis. lxxxviii, lxxxix). Typical crassi has no suggestion of either a sinus or a serration (cf. Stebbing, 1888, pi. xc). The telson is much more deeply cleft than in typical crassi. In the above comparison I have referred throughout to typical crassi, i.e. the Chal- lenger specimen from off Monte Video. This is necessary because Stebbing himself has recorded crassi from South-east Australia and expressed doubt as to whether crassi can be maintained as a species distinct from monoculoides . The presence of two serrations on pleon segment 3 in the Australian specimen seems to imply that it should have been referred to monoculoides. I do not consider the Australian "crassi" to be synonymous with the true Atlantic crassi. Whether georgianus will prove to be really distinct from crassi is a different matter. Fig. 116. Eusiroides georgianus, n.sp. a. Pleon segment 3. b. Portion of integument highly magnified, c. Telson, with apex of one lobe highly magnified to show sculpture. Eusiroides stenopleura, n.sp. (Fig. 117 and PI. I, fig. 4). Occurrence: 1. St. 71. South-west Atlantic. 1^15 mm., 1 juv. 13 mm. 2. St. 114. Bouvet Island. 1 ovig. 924 mm. 3. St. 239. South-west Atlantic. 2 ?? 19 and 25 mm. Types. EUSIRIDAE i93 Description. Close to crassi, Stebb. All side-plates considerably shallower than their segments; 1-4 longer than deep; 1 subquadrangular, not projecting below inferior margin of head, scarcely produced forwards, but antero-inferior angle quadrate. All peraeon segments rounded dorsally. Postero-inferior angle of pleon segment 3 quadrate, margin entire. Telson cleft for a little more than half its length, apices acute. Antenna 1, accessory flagellum obsolete. Lower margin of flagellum of antenna 1, and upper margin of flagellum and 5th peduncular joint of antenna 2 calceoliferous. Mandible with 2nd palpal joint very broad. Fig. 117. Eusiroides stenopkura, n.sp. a. Head, peraeon segments 1 and 2, with side-plates; the dotted line indicates the extent of the reddish pigment, b. Side-plate 4. c. Mandible, d. Maxilla 1, with spine from outer lobe further enlarged, e. 2nd joint of peraeopod 5 with hind margin further enlarged. /. Telson. Gnathopods 1 and 2, palm of hand evenly convex as in crassi, defined by one spine proximally. Peraeopods 3-5, 2nd joint with hind margin entire, or, in peraeopod 5, very feebly indented. Otherwise resembling crassi. Remarks. These specimens certainly represent a distinct species; the shallow side- plates separate it from all the others. The faceted eyes are reniform and, as preserved, reddish ; but lying within the cuticle and occupying nearly the whole of the side of the head is a round patch of reddish pig- ment, dorsally almost contiguous with its fellow. Compare Strauss' figures of the form he calls Rhachotropis diploops, n.sp., captured by the ' Valdivia' at St. 54 in the Atlantic (i° 51' N, o° 31' E). Strauss (1909, p. 38, pi. iv, figs. 24, 25) gives no description, except of the eye, by which the species can be identified and Schellenberg (1926 b) makes no mention of it. Strauss' fig. 24 would fit the present specimens as regards the rostrum (for this reason his specimen was certainly not a Rhachotropis), the mandibular palp, and the antennae, but not the 1st side-plate. The anterior margin of the latter is just indicated by Strauss and shows a rounded antero-inferior angle projecting considerably below the 2 5 I94 DISCOVERY REPORTS inferior margin of head. This is possibly not to be taken too seriously, as Strauss was concerned with the eye-structure only, and, as mentioned elsewhere, was not a syste- matise Nevertheless, in spite of the evident similarity in the eye-structure, I do not think the present specimens should be identified with " Rhachotropis diploops", which remains in any case a nomen nudum. Genus Eusirella, Chevr. Chevreux, 190S (Bull. Inst, ocean. Monaco, no. 121), p. 12. Schellenberg, 1926 b, p. 228. Eusirella elegans, Chevr. Chevreux, 1908 (loc. cit.), p. 12, figs. 7, 8. Schellenberg, 1926 b, p. 228, fig. 19 (valdiviae). Occurrence: St. 87. South-east Atlantic. 1 <$ 8-5 mm. Remarks. This specimen shows that both the Princess Alice and the Valdivia specimens were but immature forms of the same species, the former possibly $, the latter probably 6*. No trace of eyes. Telson with the lobes only distally dehiscent, apices acute, each with a very minute notch and setule (only seen under high magnification) . Antenna 1, 1st peduncular joint with a small point on upper apex and a strong tooth bearing two setae on lower apex; this tooth in lateral view is acute, but in ventral view is chisel-shaped; 2nd joint with an apical point above, and two setae below, densely calceoliferous on lower and inner surfaces, flagellum 18-jointed, calceoliferous, accessory fiagellum not visible. Antenna 2, 4th joint on upper and inner surfaces, and 5th joint on upper, lower, and inner surfaces densely calceoliferous, flagellum plump, 8-jointed, calceoliferous. Gnathopods 1 and 2, palm with a row of spines and defined by two to three spines. Uropods, rami sparsely spinulose, with the margins very minutely serrulate. The locality of the ' Discovery' is close to that of the 'Valdivia'. Distribution. Azores, 38 N, 26 W, 0-2500 m.; South-east Atlantic, 3i°2i'S, 9 46' E, 3000-0 m. Genus Rhachotropis, S. I. Smith. Stebbing, 1906, p. 347. Barnard, 1916, p. 178. As mentioned above (p. 193) Rhachotropis diploops, Strauss, 1909, besides being a nomen nudum, is not to be reckoned as belonging to this genus. Rhachotropis antarctica, n.sp. Occurrence: 1. St. 51. Falklands. 3 S3 7-10 mm., 6 ?$ (2 ovig. 1 with embryos) 7-9 mm. 2. St. 144. South Georgia. ii??(i ovig. with embryos) n-13 mm., 2 immat. 8mm. 3. St. 167. South Orkneys. 2 cfc? 10-11 mm., 5 ?? 13-14 mm., 2 immat. $$ 9 and 1 1 mm. Types. 4. St. 170. South Shetlands. Fourteen specimens, mostly mutilated, incl. ovig. $$, 14-20 mm. PONTOGENEIIDAE 195 5. St. 175. South Shetlands. 1 c? 18 mm., 19 $$ 16-18 mm., 1 ovig. $ 20 mm. Four mutilated specimens. 6. St. 181. Palmer Archipelago. 10 9? 12-20 mm. 7. St. 182. Palmer Archipelago. 1 ? 16 mm. 8. St. 187. Palmer Archipelago. 16*11 mm., 1 ovig. $15 mm. 9. St. 190. Palmer Archipelago (315 m.). 2 6*6* 17 mm., 1 $ 15 mm. (somewhat mutilated). Description. Close to inflata (Sars) but: pleon segments 1-4 tricarinate, all the carinae produced into small acute teeth except the medio-dorsal one on segment 3, and the dorso-lateral ones on segment 4 ; and telson cleft for not more than, or scarcely more than (St. 51), one-third its length. Remarks. The much larger size and the fact that pleon segment 4 is tricarinate as well as the preceding three segments distinguishes this species from its northern counterpart inflata. From rostrata (Bonn.) it differs in having dorso-lateral keels on pleon segment 1 as well as on the three following segments, and well- developed eyes. The smaller specimens from St. 51 do not appear to differ in any way from the others except in the slightly deeper telsonic cleft. Family PONTOGENEIIDAE Stebbing, 1906, pp. 356, 729. Schellenberg, 1929 a, p. 273 (revision, with key to genera). The representatives of this family have hitherto been involved in considerable con- fusion, and we have to thank Schellenberg for a most useful revision with sharp delimitations of the various genera. But, needless to add, many of the earlier species are still obscure, and only an examination of material collected in the original localities, and a re-examination of the material collected by previous expeditions, will extricate and stabilise the synonymy. Chilton, relying apparently too implicitly on the assumption of "widely distributed species", did much to confuse our knowledge of the distribution of the species of this family by erroneous identifications. It is greatly to be regretted that, e.g., the Scotia material must be entirely re-examined before the localities there recorded can be available for working out the distribution of the species. In suggesting the use of one character which has only been employed previously in a few cases, no generic value is claimed for it, though it would seem to have considerable specific value. This character is the surface sculpturing of the integument. From the figures here given for all the species contained in the Discovery collection, it will be seen that the differences are of no mean order and may well be used to separate species, or per contra as an indication of affinity. It is in fact rather extraordinary that so little attention has been paid to the surface of the integument, apart from major features such as knobs, teeth, spinous processes and the like. The surface sculpture has been used to differentiate the species of Hippomedon (cf. Sars, 1895, pis. xx, xxi and Stephensen, 1923) and has been mentioned casually 196 DISCOVERY REPORTS in a few instances in the present family, e.g. Stebbing, 1888, pi. lxxv. (Paramoera australis), Chilton, 1912, p. 500 (Djerboa fnrcipes), and Monod, 1926, fig. 54 {Para- moera austrina}). A few other examples could be added, as for instance Bate's descrip- tion of the surface sculpture of Halirages huxleyanus. The figures given by Stebbing and Monod are very useful, because apart from other characters they show conclusively that Stebbing's australis and Monod's austrina cannot possibly be united with capensis. Whether Monod's austrina is the same as austrina Bate must remain undecided until Bate's type, or material from the original locality, can be examined. Although it necessitates the re-examination of much previous material, I think this is a character which should be adopted, not only in the present family, but throughout the Amphipoda and Crustacea generally. Every description of a species must be re- garded as not fully complete which does not contain a mention of this "superficial" feature. The present writer fully admits his own deficiencies in this respect. This feature would have been mentioned throughout this report had not the present family, being a difficult one, been left until last, and the importance of the character not fully realized until the rest of the work had been completed. I would suggest that difficult genera like Orchomene, Orchomenella and Tryphosa among the Lysianassidae be tested for this purpose. As regards technique, I need scarcely say that the integument must be carefully cleaned of all foreign matter adhering to it, and examined dry by reflected light; if not actually desiccated, there must at least be no free water or moisture on the surface. Genus Bovallia, Pfr. Pfeffer, 1888, p. 95. Stebbing, 1906, p. 357. Schellenberg, 1926, p. 354; 1929 a, p. 277. In Schellenberg's revision this genus is now monotypic, the other species formerly included in it having been transferred as follows: walkeri (Stebb.) to Paramoera, calliopioides , Schell., to Pontogeneia, and regis, Stebb., to Halirages. Bovallia gigantea, Pfr. (Fig. 118 a). Pfeffer, 1888, p. 96, pi. i, figs. 2 and 5. Chevreux, 1906, p. 54, figs. 31-33; 1913, p. 169. Chilton, 1912, p. 494 {monoculoides, non Hasw.); 1925, p. 177 {monoculoides, non Hasw.). Shoemaker, 1914, p. 74 (part, monoculoides, non Hasw.). Occurrence: 1. St. 174. South Shetlands. 1 $ 40 mm. 2. St. 179. Palmer Archipelago. 1 945 mm., 3 ?? 20-24 mm., 2 juv. 10-11 mm. 3. St. WS 56. South Georgia. 5 $$ 23-33 mm., 6 $$ 24-40 mm., kelp roots. 4. St. MS 10. South Georgia. 1 immat. $ 28 mm. 5. East Cumberland Bay, South Georgia. 1 ? 39 mm. Remarks. The integument is covered with scattered circular punctae anteriorly, passing gradually into the elongate depressions which posteriorly are arranged in more or less transverse rows, producing an imbricate appearance. PONTOGENEIIDAE 197 Now that Schellenberg has pointed out the differential characters of the lower lip, 2nd maxillae, and 1st side-plate in Bovallia and Eusiroides, which characters were not utilized by Chilton, or even by Chevreux in his " seven points " (1913), both of Pfeffer's names are vindicated. Also we are no longer under the obligation, when recording "Bovallia monoculoides", of specifying whether we mean HaswelPs form, or Pfeffer's form, or any of Stebbing's triumvirate. In fact, it is difficult to understand how the species of Eusiroides can ever have been confused with Bovallia. To Chevreux's seven points, Schellenberg has added three more; there is also the 4th side-plate, and if the character of the integument should prove to be similar in all the species of Eusiroides (cf. p. 191), twelve points of difference can be found. Consequently all records of "Bovallia monoculoides" should be omitted from geo- graphical considerations, until the specimens on which they were based have been re- examined. We may perhaps except Chilton's records (1912 and 1925) from the South .•*:. t# m m n si i« •%• * ,-. nn v ,, • »• * *?£•£* SS-S&S -Vv:S^ &£&$ * * n. h. i. j k I. m. Fig. 118. Portions of the integuments, highly magnified, of various Pontogeneiidae : a. Bovallia gigas and Djerboafurcipes. b, Eurymera monticulosa. c. Schraderia gracilis, d. Prostebbingia gracilis, e. Atyloella dentata. f. Poniogeneiella brevicornis and longicornis. g. Pontogeneia simplex and Atyloella magellanica. h. Pontogeneia antarctica and georgiana. i. Paramoera gregaria. j. Paramoera obliquimanus. k. Paramoera tristanensis. I. Paramoera walkeri and hermit ensis. m. Pontogeneia tristanensis and Paramoera edouardi and bidentata. n. Paramoera capensis. Orkneys, as he specifically refers to the dorsal teeth and absence of serration on the postero-inferior margin of pleon segment 3. Pending re-examination, one may hazard the opinion that all Australasian examples will be referred to Eusiroides [monoculoides Hasw.), but not to Bovallia. Bovallia gigantea is a perfectly well-defined species with a definite distribution. Pfeffer recorded specimens of 45 mm. length, and orange- to purple-red in colour. Chevreux (1913) records his specimens as being greenish brown, reddish above, eyes brick-red. The colour of no. 1 is given as: "Dragons-blood red (Ridgway 5' OO-R) darkest on back, palest laterally and on appendages. Eyes dark grey". Distribution. South Georgia; South Orkneys, shore and shallow water; South Shetlands, littoral; Palmer Archipelago, 0-5 m. Genus Eurymera, Pfr. Pfeffer, 1888, p. 102. Stebbing, 1906, p. 356. Schellenberg, 1929 a, p. 277. i 9 8 DISCOVERY REPORTS Eurymera monticulosa, Pfr. (Fig. 118 b). Pfeffer, 1888, p. 103, pi. i, fig. 3. Chevreux, 1906, p. 59, figs. 34-36; 191 3, p. 167. Chilton, 1912, p. 493. Shoemaker, 19 14, p. 74. Occurrence: 1. St. 174. South Shetlands. 1 ? 23 mm. 2. St. 179. Palmer Archipelago. 46 <$S and ?? up to 20 mm., 3 juv. 6-7 mm. Remarks. Integument coarsely pitted all over. Distribution. South Georgia; Graham Land, littoral; South Orkneys, 4 fathoms. Genus Pontogeneia, Boeck. Schellenberg, 1929 a, p. 277; 1931, p. 181. The number of simple unexpanded flagellar joints on antenna 1 separating every two of the dilated joints which bear sensory filaments appears to be a good specific cha- racter, but only in adult animals. Compare the adult and young of tristanensis {infra). Other characters should of course be utilized in conjunction. Pontogeneia simplex (Dana) (Fig. n&g). Dana, 1853/55, P- 9 2 ^» pi- l x i n > %• 2 - Bate, 1862, p. 140, pi. xxvii, fig. 2 (after Dana). Chilton, 1912, p. 495 (danai, non Thorns.). Schellenberg, 193 1, p. 182, fig. 93. Occurrence: St. 56. Falklands. 1 immat. $ 11 mm., 1 ovig. $ 14mm. Remarks. Integument minutely shagreened, with scattered pits. Every 5th or 6th flagellar joint on antenna 1 enlarged and bearing sensory filamentous setae. Flagella of both antennae more thickly spinulose than in antarctica, Chevr. In the present state of our knowledge I prefer to identify these specimens with Dana's species originally collected at Hermite Island than with a New Zealand species. They are in all probability adults of the same form as Chilton examined. Distribution. Hermite Island, Cape Horn; Falkland Islands. Pontogeneia georgiana (Pfr.) (Figs. 118 h, 119). Pfeffer, 1888, p. 116, pi. ii, fig. 6 (Calliopius g.). Stebbing, 1906, p. 308 (Apherusa g.). Schellenberg, 1929 a, p. 278; 1931, p. 184, fig. 94. Occurrence: East Cumberland Bay, South Georgia. 1 ? 13 mm., 2 muti- lated $?. Remarks. Although Pfeffer said that, next to Schraderia gracilis, this was the commonest Amphipod in South Georgia, there are only these three specimens in the present collection. They entirely conform with Pfeffer's description. The postero- pig. 119. Pontogeneia inferior angle of pleon segment 3 is not mentioned in the description georgiana (Pfr.). Head. PONTOGENEIIDAE i99 but the figure shows it as rounded-quadrate ; in these specimens it is broadly rounded exactly as in antarctica, Chevr. Every alternate flagellar joint of antenna i is enlarged and bears sensory setae. The integument is covered with close-set lenticular impressions (or scale-like imbrications, if preferred), more or less horizontal anteriorly, becoming vertical (transverse) on the posterior segments. Pfeffer's description of the telson is correct, except that it really is cleft ; a very slight pressure of the dissecting needle is enough to separate the two lobes. Distribution. South Georgia. Pontogeneia antarctica, Chevr. (Fig. 118 h). Chevreux, 1906, p. 69, figs. 40, 41 ; 1913, p. 177, fig. 59. Chilton, 1912, p. 496; 1925, p. 178. ? Non Stebbing, 1914, p. 364. Non Stephensen, 1927, p. 319, figs. 10, 11. Schellenberg, 193 1, p. 185. Occurrence: 1. St. 166. South Orkneys. Many $S, $$ and juv. 6-16 mm. 2. St. 179. Palmer Archipelago. 7 $$ n-12 mm., 24 $$ 11-17 mm. Remarks. Integument with close-set elongate lenticular impressions, exactly as in georgiana. Every 3rd flagellar joint of antenna 1 enlarged. I fail to find any characters separating this species from georgiana except the number of joints separating every pair of enlarged joints on antenna 1. The anterior margin of the head is the same in the actual specimens, though Chevreux's figure of this in antarctica differs slightly, but not essentially, from that here given for georgiana. The straight line forming the junctions of the side-plates with the peraeon segments in Chevreux's figure appears diagrammatic when compared with the actual specimens ; Pfeffer's description and figure fit these specimens perfectly. It is of course only a phenomenon of preservation, but many of these specimens exhibit the same loosely articulated segments as described by Pfeffer in georgiana. Distribution. Graham Land; Petermann Island; South Shetlands; South Orkneys, 0-6 m. Pontogeneia tristanensis, n.sp. (Figs. 118 m, 120). Occurrence: St. 5. Tristan da Cunha. 3 $$ 6-7 mm., 2 $$ 7-9 mm., several juv. 3-5 mm. Description. Integument minutely shagreened, without pits. Postantennal angle of head quadrate, the actual angle rounded. Eyes subcircular. None of the peraeon or pleon segments dorsally dentate. Side-plates 1-4 shallow, 4 subtriangular, feebly excavate on hind margin. Pleon segment 3 narrowing below on the pleural portion, which is completely rounded on lower and hind margin. Telson twice as long as broad, of nearly equal width throughout, cleft for one-quarter its length, lobes dehiscent, apices narrowly rounded, no setules or spines. Antenna 1, flagellum with every 3rd or 4th joint in <$, every 4th joint in $, enlarged. In the young every alternate joint is enlarged. 20o DISCOVERY REPORTS Gnathopods i and 2 as in antarctica, Chevr. Peraeopods 3-5, 2nd joint in peraeopods 3 and 4 oval, in peraeopod 5 oblong, the hind margin straight or even inclined to be very slightly concave, lower hind angle rounded. Remarks. This, the first example of the genus to be recorded from this island, appears to be a good species characterized by the 4th side-plate, 3rd pleon segment, post-antennal angle of head, and eye, in combination with the flagellum of antenna 1. a. b. c d Fig. 120. Pontogeneia tristanensis, n.sp. a. Pleon segment 3. b. Telson. c. Head. d. Side-plate 4. Genus Pontogeneiella, Schell. Schellenberg, 1929 a, p. 278. In explanation of the terms " schuppen-formig " (key, p. 276) and "flache lamella" (p. 278) used by Schellenberg in describing the rudimentary accessory flagellum, it may be stated that they refer merely to the distal margin of the 3rd peduncular joint. There is no articulated accessory flagellum or rudiment thereof. Pontogeneiella brevicornis (Chevr.) (Fig. 118/). Chevreux, 1906, p. 79, figs. 45-47; 191 1, p. 403. Chilton, 1925, p. 178. Schellenberg, 1929 a, p. 278. Occurrence: 1. St. 165. South Orkneys. 1 $ 22 mm. (antennae lost) from stomach of Notothenia. 2. St. 173. South Shetlands. 5 $<$ 12-13 mm., 11 ?? 12-15 mm. 3. St. WS 56. South Georgia. 3 immat. $? 18 mm. Remarks. Integument minutely shagreened, with scattered pits. Distribution. Palmer Archipelago; South Orkneys; South Sandwich Islands. Pontogeneiella longicornis (Chevr.) (Fig. 118/). Chevreux, 1906, p. 84, figs. 48-50; 1913, p. 179. Schellenberg, 1929 a, p. 278; 1931, p. 190. Occurrence: 1. St. 190. Palmer Archipelago (315 m.). 1 immat. $ 26 mm. 2. St. WS 25. South Georgia. 1 $ 18 mm. 3. St. MS 10. South Georgia. 3 $$ 15-21 mm. 4. St. MS 67. South Georgia. 1 $ 15 mm. Remarks. Integument as in brevicornis. There would seem to be considerable likeli- hood of this species being merged in brevicornis. The serration of the hind margin of PONTOGENEIIDAE the 2nd joint of peraeopods 4 and 5, the length of the antennae, and the size of the eye, would not appear from an examination of the present specimens to be clear-cut differential features. Distribution. Palmer Archipelago, 25-129 m.; Petermann Island, 40-60 m. Genus Prostebbingia, Schell. Schellenberg, 1926, p. 357; 1929 a, p. 278. Prostebbingia gracilis (Chevr.) (Figs. 118 d, 121). Chevreux, 1913, p. 173, figs. 56-58. Schellenberg, 1926, p. 358. Occurrence: 1. St. 173. South Shetlands. Many <$<$ and $$ 5-10 mm. 2. St. 175. South Shetlands. 7 $$ 10-13 mm - 3. St. 179. Palmer Archipelago. 4 $$ 9-12 mm., 2 juv. 6 mm. 4. St. MS 67. South Georgia. Many S$ and ?$ 5-10 mm. 5. St. MS 71. South Georgia. 6 ?? 6-10 mm. 6. St. MS 74. South Georgia. 3 S fi 8 s - 5 a ~g- Bate, 1862, p. 141, pi. xxvii, fig. 4. Stebbing, 1888, p. 918, pi. lxxvii (Atyloides assimilis). Chilton, 1912, p. 499 (austrina "special variety"). Barnard, 1916, p. 183. Schellenberg, 1925, p. 149; 1926, p. 363 (f. capensis); 1929c, p. 280 (fissicauda, Dana, var. capensis). 27 2io DISCOVERY REPORTS Occurrence: St. MS 82. Saldanha Bay, South Africa. 20 ?? 5-9 mm., the larger ovig. Remarks. Integument nitidulous, with numerous pits which in the posterior seg- ments sometimes tend to become elongate so as to produce the appearance of short lines. This is especially noticeable in specimens from the more easterly localities (Port Elizabeth, East London and Natal), in which also the pits tend to be slightly stronger and closer together. Post- antennal angle of head rounded-quadrate. Schellenberg (1925) has shown that the inclusion of magellanica, Stebb. (= Atyloella m.) in the —j- synonymy which I gave in 19 16 was wrong. I agree. _ . , , , t -ii • ^ • ^l .. • Fig. 128. Paramoera capensis (Dana). On the other hand, I still maintain that austnna, B A w r a. Head. b. Pleon segment 3. excluded by me in 1916, is rightly excluded. I see no possibility of including a species with a telson like that in Bate's figure (pi. xxvi, fig. 4) with capensis. The same applies to australis, Miers. The normal telson of the adult should be used as a criterion, and in capensis it is comparatively short and broad, with multidentate apices. Moreover, the integument of austrina has yet to be recorded. In australis Stebbing describes it as scabrous on the posterior segments. In the two to three hundred speci- mens from various South African localities which I have examined, I have not found a trace of scabrous ornamentation. There would appear to be no difficulty in finding differences (integument, shape of head, pleon segment 3, telson, etc.) if one looks for them, instead of endeavouring to find points of agreement with a view to recording one "widely distributed species." Distribution. South Africa, west coast as far north as Swakopmund, south coast as far east as Port Shepstone in Natal; St Helena (Schellenberg, 1926). Paramoera bidentata, n.sp. (Figs. 118 m, 129). Occurrence: South Africa, Kalk Bay (False Bay). 1 ? 15 mm. (S.A.M. Reg. no. 1294). Description. Integument very minutely shagreened, without pits. Rostral point small, acute. Antero-lateral margin of head somewhat angular, post-antennal angle acutely produced. Eyes reniform, nearly meeting on top of head. Side-plates 1-4 moderate, lower margins not setose or serrate. Pleon segments 1 and 2 with the pos- terior margin produced in a medio-dorsal subacute triangular tooth, which is not carinal but lies flat; postero-inferior angle of segment 1 quadrate, of 2 quadrate with a very small point, the margin above slightly sinuate, of 3 quadrate with a small point, the margin above rather convex but not serrate ; segment 4 with an unusually well-marked dorsal transverse depression. Telson twice as long as broad; cleft two-thirds its length, lateral margins nearly straight, apices acute with two unequal spiniferous notches, the outer being the larger and bearing the larger spine, two submarginal unequal spines near base. GAMMARIDAE 211 Antenna i, flagellum about 55-jointed, every alternate joint expanded and bearing sensory filaments. Gnathopods 1 and 2 nearly similar, 5th joint shorter than 6th, not wider and not cup- shaped, 6th oblong, longer in gnathopod 2, palm oblique, straight, defined by two stout spines, hind margin setose. Peraeopods 3-5, 2nd joint oblong, hind margin nearly straight in peraeopod 3, straight in peraeopod 4 and slightly concave in peraeopod 5, finely serrulate, postero- inferior corners rounded, 6th with five groups of spines on anterior margin, four on posterior margin. Uropod 3, rami longer than peduncle, subequal, lanceolate, apically acute, margins with fairly closely set spinules, outer margin of outer ramus with six pairs of stouter spinules. Fig. 129. Paramoera bidentata, n.sp. a. Head. b. Pleon segments 1-4. c. Dorsal view of tooth on segment 2. d. Telson. Remarks. Similar to edouardi as regards integument, telson, and pleon segment 3, but separated by the head, dentate pleon segments 1 and 2, broader gnathopods, and oblong 2nd joints of peraeopods 3-5. Although not represented in the Discovery collection, it is convenient to describe this species alongside other species of the genus. Stebbing, 1906, pp. 364, 729. Schellenberg, 1926, p. 363. Stebbing, 1906, pp. 421, 732. Barnard, 1916, p. 189. Family GAMMARIDAE Genus Melita, Leach. Melita subchelata, Schell. (Fig. 130). Schellenberg, 1925, p. 153 {fresnelii, var. subchelata). Occurrence: St. WS Walvis Bay. 10 $$ 7-10 mm., from stomach of Trigla capensis. 27-2 212 DISCOVERY REPORTS Remarks. This form, to my mind, certainly deserves specific rank. In addition to the form of the hand of gnathopod 2 and the slight denticulation of the pleon segments, mentioned by Schellenberg, it may be stated that the 2nd joint of peraeopod 4 is pro- duced at the distal corner (in fresnelii rounded-quadrate, not produced), and the 2nd joint of peraeopod 5 is wider distally than proximally (in fresnelii, vice versa). The inner ramus of uropod 3 is present as a small rudiment. Of the present specimens six are left-handed, four right-handed. Distribution. South-west Africa, Luderitzbucht. Fig. 130. Melita subchelata, Schell. a. Gnathopod 2 o- b, c. 2nd joints of peraeopods 4 and 5. Melita inaequistylis (Dana). Stebbing, 1914, p. 366. Barnard, 1916, p. 191 (references). Stephensen, 1927, p. 345. Occurrence: St. 90. South Africa. 2 S3 9 and 12 mm., 1 juv. 8 mm. Distribution. New Zealand and neighbouring islands; Falkland Islands; Ceylon and India ; South Africa. Genus Maera, Leach. Stebbing, 1906, pp. 433, 732. Stephensen, 1925, p. 48. Maera pfefferi, n.sp. (Fig. 131). Occurrence: 1. St. 123. South Georgia. 1 l ovi §- ? 4 mm - Description. Eyes oval or subcircular. Peraeon and pleon not dorsally dentate. Side-plates entire on lower margins. Postero-inferior angle of pleon segment 3 quadrate, with a small point. Antenna 1, accessory flagellum 7-8-jointed. Gnathopod 1, 5th joint in $ with slight subapical depression on upper margin, apex slightly produced over base of 6th joint (cf.pfefferi, and footnote, infra). Gnathopod 2 in S, 6th joint oblong, nearly twice as long as broad, palm a little oblique, defined by two spiniform teeth, two small spines within the angle, one broad semicircular excision separated from a narrower excision nearer the hinge by a bifid tooth bearing two spines, a subtruncate spiniferous tooth near hinge, finger sinuate on inner margin. In immature J the hand is narrower, palm more oblique, and the excisions not so deep. In ? the hand widens slightly to the oblique, convex, crenulate palm, which is defined from the hind margin by an obtuse angle, but no projecting tooth or spine. Peraeopods 1 and 2 slender. Peraeopod 3, 2nd joint ovate, produced behind to end 1 This occurs also in Kunkel's (1910) figures of M. rathbunae, and also to a less extent in his figure of inaequipes, as well as in Chevreux and Fage's (1925) figure of inaequipes. GAMMARIDAE 215 of 3rd joint, hind margin convex, serrulate, 4th strongly expanded, almost as wide as 2nd, 5th and 6th narrow, finger with accessory denticle on outside of unguis. Peraeopods 4 and 5, 2nd joints resembling that of peraeopod 3, 4th joint not expanded, twice as long as wide. Uropod 3, rami not extending beyond apices of rami of uropod 1, apices truncate. Fig. 132. Maera ascensionis, n.sp. a. Gnathopod 2$. b. Gnathopod 2 of young Qrtm , from a specimen not fully flattened out, which would Dorsal view of left uropod 3 of: a. Speci- account for the narrowness of these joints. In other men from shore, b. Specimen from respects the coastal specimens agree with Ortmann's lakes - figures. On the other hand, the specimens from the lakes at a higher altitude, while agreeing in most respects with the coastal specimens, differ in two* respects. The 3rd uropod is slightly longer and less robust, the outer margin of the peduncle being straight instead of 220 DISCOVERY REPORTS convex, and having a group of spines aggregated at the inner apex instead of three large ones distributed along the margin. The ist gnathopod of the <$ is not strongly expanded distally, and thus resembles more the ist gnathopod of the $ of the coastal form. In the absence of more abundant material, the best course is to regard these two sets of specimens as forms of the same species, and to identify them with Ortmann's species. Distribution. Patagonia, 47°-5o° S, from coast up to 2000 ft. in the Cordilleras; Magellan Strait; Falkland Islands. Genus Allorchestes, Dana. Stebbing, 1906, p. 581. Chilton, 1926, p. 515. Allorchestes patagonicus, Cunningham (1871), remains obscure. It may be the same as Hyalella patagonica, Ortm., supra, but unless Cunningham's type can be found, it would be better to ignore his species. Allorchestes sp. Occurrence: St. WS 123. Gough Island. 1 immat. 9 « mm. (shore). Remarks. It is unfortunate that there is only this single ? specimen, as no member of this genus has hitherto been recorded from either Tristan da Cunha or Gough Island. Maxillary palp extending to apex of outer lobe. Gnathopod 2 a little longer than gnathopod 1, 2nd joint in both rather strongly keeled on anterior margin, 5th com- parable with that figured for gnathopod 1 of plnmicornis (Stebbing, 1899, Trans. Linn. Soc. Lond. (2), vii, pi. xxxiii C), equally strong in gnathopod 2, 6th broadly oval, especially in gnathopod 2. Family AORIDAE Stebbing, 1906, pp. 585, 736. Schellenberg, 1925, p. 164. Members of this family, though recorded from the sub-Antarctic (Kerguelen and South America) appear to be rare in the Antarctic regions. Some specimens were col- lected by the ' Gauss' but Schellenberg (1926, p. 374, fig. 60) was unable to refer them to any particular genus or species on account of the absence of the 6* . All the Discovery examples of this family were obtained in South African waters with the exception of two specimens from the Falkland Islands. Genus Aora, Kroy. Stebbing, 1906, p. 587. Aora typica, Kroy. Stebbing, 1906, p. 587, fig. 101. Barnard, 1916, p. 236 (literature). Schellenberg, 1926, p. 372 (fig. 59, forma anomala). forma gibbula, n. (Fig. 135). Schellenberg, 1926, p. 372. Occurrence : St. 91. South Africa. 9 4 mm. Description. Body rather depressed, the back broadly rounded. Rostral point minute, ocular angle rounded, almost truncate. Eyes well developed, small, oval, dark. Side-plate 1 small, shallow, produced forwards, with three setae on rounded apex; 2 much larger, also produced forwards, with setae on lower margin; 3 and 4 a trifle deeper than long, setose on lower margin; anterior lobe of 5 as deep as side-plate 4. Fig. 149. Kuphocheira setirnanus, Brnrd. a. Lower lip. h. Mandible with molar further enlarged, c. Maxilla 1. d. Maxilla 2. e. Maxilliped. /. 3rd~5th peduncular joints and flagellum of antenna 2 7 ?? (some ovig.) 5-5-7 mm., S juv. 4 5 mm. 2. Hast Cumberland Hay, South Georgia. Several <$<$ and ?$ (inch ovig. YY but no adult o* v 33 2S 8 DISCOVERY REPORTS Family SCINIDAE Stebbing, 1904, p. 18. Wagler, 1926 (revision of family); 1927. Besides Scina there are two other genera in this family: Acanthoscina and Ctenoscina, but neither of these is represented in the Discovery collection. Genus Scina, Prest. Stebbing, 1904, p. 22 (key to species). Stephensen, 1918, p. 19. Wagler, 1926 (revision and key to species). Of the twenty-seven species described and figured in Wagler 's useful monograph the 'Discovery' has taken twelve. Amongst them there are representatives of all six groups except the latifrons group. It is to be noted that not a single specimen of this genus was taken by the ' Discovery ' in the Drake Strait or South Georgia regions. The only existing record of a Scina from these regions seems to be Bovallius' record of Scina tnllbergi from off Cape Horn. On the other hand, the ' Valdivia' took numerous examples of S. antarctica Wagl. from the area between Bouvet Island and Enderby Land (cf. also Wagler, 1927, p. 105). Scina crassicornis (Fabr.). Stebbing, 1904, p. 24. Stephensen, 1918, p. 19, chart 2; 1923, p. 9. Chevreux, 1919, p. 10. Wagler, 1926, p. 324, figs. 2, 3; 1927, p. 90, fig. 1. Barnard, 1930, p. 401. Occurrence: 1. St. 29 26' N, 15 07' W. 1 ? 6 mm., 1 juv. 4 mm. 2. St. 80. South Atlantic. 1 9 8 mm. 3. St. 81. South Atlantic. 1 $ 12 mm., 4?$ 10-12 mm. 4. St. 83. South-east Atlantic. 1 <$ 10 mm., 2 99 9 and 11 mm. 5. St. 86. South-east Atlantic. 1 $ 12 mm. 6. St. 87. South-east Atlantic. 1 9 14 mm. 7. St. 89. South-east Atlantic. 1 $ 9 mm. 8. St. 254. South-east Atlantic. 1 ? 18 mm. 9. St. 259. South-east Atlantic. 2 99 15 and 18 mm. 10. St. 268. South-east Atlantic. 1 ^ 10 mm., 1 9 12 mm. 11. St. 273. East mid-Atlantic. 2 99 11 and 13 mm., 1 ovig. 9 14 mm. 12. St. 276. East mid-Atlantic. 1 9 13 mm. 13. St. 281. East mid-Atlantic. 2 99 14 and 18 mm., 1 ovig. 9 13 mm. 14. St. 285. East mid-Atlantic. 1 $ 13 mm., 2 99 IJ mm., 4 99 16-21 mm. 15. St. 286. East mid-Atlantic. 1 P- 9^- Pirlot, 1929, p. 68, fig. 5 (crassipes). Occurrence: St. 81. South Atlantic. 1 ? 5 mm. Remarks. The single specimen has the 2nd joint of peraeopods 3 and 4, and the uropods broadened as in the <^, yet it seems to be undoubtedly a $. Wagler suspects that the differences between submarginata and marginata will eventually be shown to be due to sex and age changes. Chevreux (1919) has already reduced submarginata to a synonym. Distribution. Mediterranean; North Atlantic, 53°-26°N; South Atlantic, about 4°-55° S; Indian Ocean. Scina oedicarpus, Stebb. Wagler, 1926, p. 369, figs. 25, 26; 1927, p. 99, fig. 5. Occurrence: 1. St. 89. South-east Atlantic. 1 $ 6-5 mm. 2. St. 266. South-east Atlantic. 1 $ 6 mm. Distribution. Atlantic, 7 N-33 S; Indian Ocean. Scina wolterecki, Wagl. Wagler, 1926, p. 372, figs. 27, 28; 1927, p. 100. Occurrence : St. 256. South-east Atlantic. 1 $ 7 mm. Remarks. The inner margin of uropod 1 has three large spines on the left side, two on the right, instead of the single one opposite the outer ramus ; otherwise the specimen is in agreement with Wagler 's description and figures. Distribution. Atlantic, 2° N-33 S ; Indian Ocean. Scina rattrayi, Stebb. Stebbing, 1904, p. 26. Stephensen, 1918, p. 29; 1923, p. 9. Wagler, 1926, p. 375, figs. 29-32. Occurrence: St. 295. East mid-Atlantic. 1 . St. 268. South-east Atlantic. 2 ?$ 8-8-5 mm - 7. St. 270. South-east Atlantic. 1 ovig. $ 8 mm. Remarks. Breeding ?? have been found in the North Atlantic in March and October (Stephensen). VIBILIIDAE 2 6 3 Distribution. Mediterranean; Atlantic, 45 N-35 S; Indian Ocean; Pacific Ocean. 0-4000 m. Vibilia propinqua, Stebb. Behning, 1913, p. 218; 1925, p. 484, figs. 23-25; 1927, p. 118. Stewart, 1913, p. 246. Stephensen, 1918, p. 43, fig. 14. Barnard, 1930, p. 404. Non Walker, 1907, p. 6 (= ant arc tied). Occurrence: 1. St. 87. South-east Atlantic. 1 ? 7 mm. 2. St. 89. South-east Atlantic. 1 $ 8 mm., 2 ?$ 7-5-8-5 mm., 3 juv. 5 mm. Distribution. Mediterranean; Atlantic, 50^-34° S; Indian Ocean; Eastern Pacific. Vibilia antarctica Stebb. Walker, 1907, p. 6 (propinqua, non Stebb.). Behning, 1913, p. 219; 1925, p. 486, figs. 26-31; 1927, p. 118. Chilton, 1912, p. 514. Barnard, 1930, p. 404. Occurrence: 1. St. MS 30. South Georgia. 1 $ 13 mm. 2. St. 36. South Georgia (50-0 m.). 1 J n mm. 3. ditto (90-0 m.). 2 $$ n-12 mm., 1 $ 8 mm., 1 juv. 6-5 mm. 4. St. 46. South-west Atlantic. 1 $ 8-5 mm. 5. St. 47. Falklands. 10 $? and juv. 5-9 mm. 6. St. 49. Falklands. 1 $ 8-5 mm. 7. St. 62. South-west Atlantic. 1 $ 9 mm., 1 $ 8 mm., 1 ovig. ? 8 mm. 8. St. 71. South-west Atlantic. 2 ?? 7 and 9 mm. 9. St. 1 16. Bouvet Island. 3 <$$ 12-13 mm -» 8 ?? 10-12 mm., 9 juv. 5-6 mm. 10. St. 120. South Atlantic. 1 juv. 7 mm. 11. St. 125. South Georgia. 2 ?? 11 mm. 12. St. 129. South Georgia (84-0 m.). 2 <$3, 3 $? 9-12 mm. (1 ovig. $ 12 mm.). 13. ditto (0-5 m.). 6 2 J uv - 6-7 mm. 17. ditto (90-0 m.). 2 $? 12 mm. 18. St. 137. South Georgia. 4 <$$, 24 ?? 10-13 mm - 19. St. 138. South Georgia. 7 $? n-13 mm. (2 ovig.). 20. St. 151. South Georgia. 9 $$ 12-14 mm., 2 $$ 11 and 12 mm. 21. St. 169. South Orkneys. 7 $$ 13-14 mm., 5 ovig. $? 12-14 mm. 22. St. 208. South Shetlands. 11 ovig. $? 12-14 mm. 23. St. WS 38. South Georgia. 4 JJ, 82 ?? (many ovig.) 12-14 mm. Remarks. In this collection there are 195 $? and only 42 £3. Ovigerous ?$ were caught to the number of 22 (nos. 7, 12, 13, 19, 21 and 22), but in addition quite a lot at St. WS 38 (no. 23). They were caught in the following months: December (South Georgia area), February (South Orkneys), April (South Shetlands), and May (South- west Atlantic). 264 DISCOVERY REPORTS Although the material is not very large, it serves to indicate that this species ascends to the upper layers during the night. On only two occasions (nos. i and 19) has it been found during the day at a depth less than 100 m. ; but it occurs frequently in this upper zone between the hours of (approx.) 8 p.m. and 6 a.m. The negative evidence, though derived from only three stations, confirms this: at St. 71 six other hauls between 1000-0 m. and at St. 120 one other haul at 340-360 (-0) m. were made, but no specimens obtained; at St. 151, 15 hauls were made between 1275-0 m., and specimens were only taken at 500-625 m. The carpal process of gnathopod 2 does not always reach quite to the end of the metacarpus, but is often not more than two-thirds the length of the latter. The eyes according to Behning are poorly developed, the individual ocelli discernible only with difficulty or not at all. In all the present specimens, as in those of the Terra Nova collection, the eyes are quite well developed and the ocelli easily discernible ; they only differ from those of most other species in being of a paler reddish-brown instead of a dark brown or blackish colour. As already stated I think it very probable that the true name for these specimens should be edwardsii, Bate (1861, Ann. Mag. Nat. Hist. (3), vm, redescribed as a n.sp. in 1862, p. 300, pi. xlix, figs. 6, 7), the original locality of which was the Powell Islands (South Orkneys). There is, however, no specimen actually comparable as regards the length of peraeopods 3 and 4 with Bate's figure, or even with longipes. A re-examination of Bate's type, if still extant, especially the details of the serrations of the uropods, might be interesting in comparison with the specimens referred to antarctica by Behning. Distribution. This typical Antarctic and sub-Antarctic species extends northwards up the west coasts of Africa and South America in the cold Benguella and Chilean currents. The Scotia record is the only previous record anywhere in the neighbourhood of the present localities, the most northerly of which is St. 71 (43 ° S, 46 W). Vibilia australis, Stebb. Stebbing, 1888, p. 1287, pi. cxlix. Behning, 1913, p. 219; 1925, p. 488, figs. 32-34; and var. pelagica, p. 488, figs. 35-41; 1927, p. 119. Spandl., 1924, p. 21. Occurrence: St. 67. South-west Atlantic. 6 $? 4 mm., 1 ovig. $ 5 mm. Distribution. Atlantic, o°-2-F N; Red Sea; Indian Ocean, 6° N, 73 E; South of Australia, 48 18' S, 130 4' E. Vibilia armata, Bov. Behning, 1913, p. 220; 1925, p. 491, figs. 52-61 (synonymy); 1927, p. 119. Stephensen, 1918, p. 46, figs. 15, 16, chart 6. Barnard, 1930, p. 404. Occurrence: 1. St. 4. Tristan da Cunha. 1 $ 8 mm., 7 juv. 3-6 mm., from stomach of Blue Fish, " Perca antarctica". 2. St. 71. South-west Atlantic. 1 > ' Challenger ' Plankton Exp. 'Gauss' 35° N, North Sargasso Sea 35° S, Atlantic Ocean 28 January 19 October 16 November )> ' Discovery ' 4i°N, i3°N, 10 October 28 October fabricii africanum ' Pieter Faure ' 5°N, o° 46' S, 33 S, Indian Ocean 25 August 12 August 22 April The collection of the ' Thor ' was made during the months of February (one larva) and May, June and September, but no adult female was taken. Our knowledge of the geographical distribution of the genus has been considerably extended by the Discovery captures. The most southerly records hitherto known were: 1 This is the only ? that Woltereck explicitly states (and figures) to be "ripe", i.e. with enlarged 6th joint to peraeopod 5. 272 DISCOVERY REPORTS 33 S, 17 E (coalitum, ' Valdivia ') ; 33^-° S, 28 E (africanum, 'Pieter Faure'); and 35^° S, 8° E {magnum and pellucidnm, 'Gauss'). The 'Discovery' has extended the known southerly limit to 57— 58 S (Drake Strait) for the species fabricii. Cystisoma pellucidum (W. Suhm). Stephensen, 1918, p. 64, figs. 19, 24-27. Occurrence: 1. St. 41 ° 37' N, 12 30' W. 1 adult $ 66 mm. (incl. uropods 75 mm.). 2. St. 13° 25' N, 18° 22' W. 1 ? probably about 70 mm. (pleon and uropods missing). 3. St. 6° 55' N, 1 5 54' W. 1 immat. 40 mm. 4. St. 78. South Atlantic. 1 juv. 1 1 mm. 5. St. 281. East mid-Atlantic. 1 immat. 30 mm. 6. St. 295. East mid-Atlantic. 1 adult ? 70 mm. (incl. uropods 85 mm.). Remarks. There are five pairs of ventral spines, except in no. 1 where there are five spines on the left side, six on the right, and in nos. 2 and 4 where there are only four pairs. Nos. 1 and 6 have the elongate outer rami to the uropods and the enlarged antennae and 6th joint to peraeopod 5. The antennae are about the same length as the head, except in no. 2 where they are distinctly shorter (13 : 20) ; they are 6 mm. apart, except in no. 3 where they are only 3 mm., the antennae and head of the latter both measuring 11 mm., and in no. 4 where they are 2 mm. long and 1 mm. apart. A remarkable feature of nos. 1 and 6 is the presence of numerous minute Copepods within the body; they occur in all parts of the body, in no. 1 even within the peduncles of the pleopods and the basal (2nd) joints of peraeopods 4 and 7. Their presence has not been noticed by other authors, and they are not present in africanum (which I have re-examined), or the other large Discovery $ no. 2. The only explanation I have to suggest is that nos. 1 and 4 were " spent" ?? and were mere dead skins when captured, the minute Copepods having entered the bodies in the role of scavengers. Whether W. Suhm's species should be identified with " spinosum" of Fabricius and/or Guerin is impossible to say, and it seems best to drop the name "spinosum" altogether. Distribution. North Atlantic, 48°-35°N; Indian Ocean, o° 58-4; 1 - S. 1280- 4000 m. Cystisoma fabricii, Stebb. Stephensen, 1918, p. 63, figs. 22, 23. Occurrence: 1. St. 13 25' N, 18 22' W. 2 $$ 65 and 66 mm. (incl. uropods 72 and 76 mm.), 3 immat. 34, 40, and 48 mm. 2. St. 6° 55' N, 1 5 54' W. 2 immat. 25 and 40 mm. 3. St. 71. South-west Atlantic. 1 immat. 35 mm. 4. St. 81. South Atlantic. 1 $ 52 mm. (no genital papillae or median ventral spine). 5. St. 216. Drake Strait. 1 juv. 21 mm. 6. St. 219. Drake Strait. 1 juv. 23 mm. 7. St. 276. East mid-Atlantic. 1 juv. 17 mm. 8. St. 281. East mid-Atlantic. 1 $ 70 mm. 9. St. 287. East mid-Atlantic. 1 immat. 38 mm. 10. St. 297. East mid-Atlantic. 1 immat. 31 mm., 1 juv. 13 mm. HYPERIIDAE , 73 Remarks. In all these specimens the antennae are about as long as the head, some- times a little less, sometimes a little more; except in one specimen of no. i where they are considerably longer (head n mm., antennae 20 mm., total length 48 mm.); they always arise close together, never more than 1-5 mm. apart in the largest specimens. The number of ventral spines is constant (two pairs). No. 5 is noted as being "completely transparent". Woltereck(ioo3, p. 452) found rows of regularly spaced chromatophores on the edges of the peraeopods and the dorsal keels. Nos. 3, 4, and especially 5 and 6, extend the known distribution far to the south. Distribution. North Atlantic, 5o°N; Indo-Pacific (Zanzibar and East Indies), 4 N-io° S. 900-2200 m. Family HYPERIIDAE Bovallius, 1889, p. 74 (key to genera). Stephensen, 1924, p. 78. Spandl, 1927, p. 151 (key to genera). Genus Hyperia, Latr. Bovallius, 1889, p. 129 (key to species). Vosseler, 1901, p. 56. Spandl, 1927, p. 153. Hyperia galba, Mont. Barnard, 1916, p. 285 (gaudichaudii) (literature); 1930, p. 411. Stephensen, 1924, p. 81, chart n. Spandl, 1927, p. 153. Occurrence: 1. St. WS Hoetjes Bay, South Africa. 1 adult <$ 12 mm., 2 cJc? (penult, instar) 11 mm., 4 $$ 8-1 1 mm., from Medusae. 2. St. WS 95. Between Falklands and South America. 1 £ (penult, instar) 9 mm., 12 $$ 8-10 mm. (the larger ovig.). Remarks. In the Terra Nova Report I maintained that gaudichaudii was not separable from galba, and further that spinigera and antarctica were also synonymous. Since, however, I have seen the specimens in the present collection which are obviously re- ferable to the form spinigera, I am of opinion that spinigera ought to be kept separate from galba. Distribution. Mediterranean; North Atlantic, southwards to i7°N; South Atlantic, northwards to 26^° S; Arctic and Antarctic Oceans; Indo-Pacific. Hyperia spinigera, Bov. (Fig. 160). Bovallius, 1889, p. 191, pi. x, figs. 33-39. Norman, 1900, p. 128 (galba part). Tattersall, 1906, p. 22. Stephensen, 1924, p. 81 (galba part). Spandl, 1927, p. 153, fig. 2 (antarctica). Occurrence: 1. St. 36. South Georgia. 1 £ 22 mm. (mutilated). 2. St. 298. East mid-Atlantic. 1 $ 20 mm., 1 ovig. $ 15 mm. D v 35 274 DISCOVERY REPORTS Remarks. Firstly, it seems reasonable to assume that the ? and £ of no. 2 are con- specific, though it is not certain. The most striking feature of both is the very broad peduncles and inner rami of uropods 2 and 3 ; that of the S agrees with Bovallius' figure of a 25 mm. in house. 11. St. 72. South-west Atlantic. 3 $? 22-25 mm. with three houses. 12. St. 76. South-west Atlantic. 1 $ 26 mm. in house, with juv. in 2nd instar. 13. St. 81. South Atlantic. 3 $$ 20-32 mm. in houses; numerous juv. in 4th and 5th instars loose in bottle. 14. St. 85. South-east Atlantic. 3 ?? 21-23 mm., two in houses, one loose. 15. St. 86. South-east Atlantic. 1 $ 18 mm. 16. St. 88. South-east Atlantic. 1 $ 28 mm. in house. 17. St. 101. South-east Atlantic (2480-2580 m.). 2 ?? 17 and 25 mm. 18. ditto (350-400-0 m.). 1 ovig. $ 31 mm., 1 ? 29 mm. with juv. in 1st instar in brood pouch; 7 $$ 17-30 mm. 19. ditto (850-900 m.). 4 $$ 15-17 mm. 20. St. 239. South-west Atlantic. 7 ?? 16-26 mm. and four houses. In one house juv. in 3rd instar, in another juv. in 2nd instar. 21. St. 250. South Atlantic. 4 ?? 22-27 mm. with houses; 1 ? 26 mm. with juv. in 1st instar in brood pouch. One house with juv. in 3rd instar, another with juv. in 4th instar. 22. St. 254. South-east Atlantic. 5 ?? 20-30 mm. and five houses. In one house juv. in 3rd and 4th instars. 23. St. 256. South-east Atlantic. 1 $ 9 mm. 24. St. 268. Portuguese West Africa. 6 SS 8-10 mm., 8 $$ 9-12 mm., 9 ?? 20- 24 mm. One house with juv. in 1st instar. 25. St. 273. Portuguese West Africa. 2 $$ 16 and 22 mm. 26. St. 281. East mid-Atlantic. 2 ?? 20 and 22 mm. 27. St. 285. East mid-Atlantic. 48 ?? 20-30 mm. with houses; 1 ovig. $ 27 mm., 2 $$ 12 and 18 mm., two houses with juv. in 2nd instar. 28. St. 297. East mid-Atlantic. 2 $$ 26 mm. with houses, and one 20 mm. loose. 29. St. WS 95. Between Falklands and South America. 1 $ 23 mm. in house. 30. St. WS 105. Between Falklands and South America. 1 ? 22 mm. in house with juv. in 3rd instar. Remarks. The adults of both sexes appear to be found mostly in the deeper layers, but the young rise to the surface (Stephensen, 1924, p. 119). Propagation takes place in winter and early spring (November to April) or in the more northerly parts of 36-2 284 DISCOVERY REPORTS the area of distribution in summer and autumn (Stephensen, 1924, p. 119). The young up to and including the 4 th insta r remain within the house (Mogk, 1927, p. 130). These observations are borne out by the present collection. Females with ova were found in October (33°-34° S) and November (3 S), with young in the 1st instar in November (33°-34° S). Young in the 2nd instar were found in June (40 S), in the 3rd and 4th instars in both June (35°-46° S) and October (13 N), in the 5th instar in June (32 S) (latitudes approximate). Dudich (1926, p. 130) does not admit Stephensen's views, and states that in the Mediterranean there are two "swarms". The autumn swarm rises to the surface and propagates in November to December. The young sink in January and grow in the deeper layers until October, when they rise again. The spring swarm rises in February, propagates in March to April ; the young sink and remain below until February. Thus at the surface from October to May there are two maxima or swarms, while in the deeper layers from May to October there are all stages of both swarms, those of the autumn swarm being more advanced. The times of appearance and bathymetrical distribution are similar to those of Pyrosoma (p. 133). The 1st instar is passed within the brood pouch of the mother (cf. no. 18); the 2nd to 4th instars are attached to the wall of the house. Stephensen (1924, p. 1 19) says that ^the young are attached in two groups and refers to a figure in Minkiewicz (1909, fig. 22 on p. 2). Minkiewicz does not specifically state the position of the larvae, and his figure may be misleading as it may represent a schematic sagittal section of the animal in its house, after removal of one side of the house on which there may have been a further batch of larvae connecting the two batches drawn in the figure. Stephensen's observa- tions, if they are his own first-hand observations, are in conflict with what I find to be the case in the Discovery material. Here there are twelve houses containing young, and in every case there is only one group. The young are arranged in a radiating manner, their heads pointing_in a centrifugal direction. Dudich (pp. 123, 124) says that the larvae feed o n the substance of the house, and as they seek for new pastures the "Brutgurtel" spreads and resolves itself into two girdles. In two cases, no. 3 (October) and no. 22 (June), the group of larvae is composed of individuals in two stages of growth, namely the 3rd and 4th instars. Where the group is composed of individuals all of the same instar, it forms a compact more or less circular patch ; but where two instars are present the number of individuals is much greater and they spread out over the whole inside of the house, though they are just as closely packed as in the groups containing only one instar. The question arises where two instars are present, whether they all belongjo_cme br ood or to two -broods. Appearances certainly seem to suggest two broods, but one may doubt the possibility of a single female producing two broods in such rapid suc- cession. Further observations on more abundant material might lead to a definite con- clusion. Dudich (p. 124) states that the eggs are laid in three batches at three-day intervals. Distribution. Mediterranean ; North and South Atlantic, 6o° N-36 S ; Indo-Pacific. PHRONIMIDAE 285 Phronima atlantica, Guer. Vosseler, 1901, p. 21, pi. ii, figs. 1-10. Stephensen, 1924, p. 121, chart 16. Mogk, 1927, p. 131, chart 2. Barnard, 1930, p. 422. Occurrence: 1. St. 39 05' N, 13 04' W. 1 3 8 mm., 1 $ 10 mm. 2. St. 2 20' S, 12 45' W. 1 3 7 mm., 1 ? 8 mm. 3. St. 87. South-east Atlantic. 5 33 5-10 mm., 8 ?$ and juv. 4-10 mm. 4. St. 89. South-east Atlantic. 9 33 6-10 mm., 9 $$ and juv. 4-14 mm. Remarks. Propagation appears to take place during both summer and winter, but chiefly in summer (Vosseler, p. 26; Stephensen, p. 124). Mogk (p. 131) records 33 in the penultimate stage in August to October. Vosseler (p. 26) refers to the possibility of there being two broods a year, which is interesting in comparison with the remarks made under sedentaria. None of the present 33 are fully adult, even the largest from St. 87 and 89, which are even larger than the normal size recorded, although only in the penultimate stage. Distribution. Mediterranean; North and South Atlantic, 4i°N-40°S; Indian Ocean, 28°-39° S; Pacific Ocean, 37 N-30 S and Chilean coast; Antarctic, 65 S, 88° E. Phronima curvipes, Voss. Vosseler, 1901, p. 27, pi. iii, figs. 1-3. Stephensen, 1924, p. 126, fig. 52, chart 17. Mogk, 1927, p. 137, chart 6. Occurrence: 1. St. 3 50' S, 12 54' W. 1 ovig. ? 13 mm. 2. St. 81. South Atlantic. 1 ? 13 mm. 3. St. 285. East mid- Atlantic. 1 914 mm. 4. St. 288. East mid-Atlantic. 1 ovig. 12 mm. 5. St. 296. East mid-Atlantic. 1 $ 1 1 mm. Remarks. The 3 of this species is known only from the Gauss expedition, and Mogk expresses a certain hesitation in the identification. Ovigerous $? are known varying from ii mm. (Stephensen), 14-16 mm. (Mogk), to 17 mm. (Vosseler); they have been found in June to September (Stephensen) and September (Mogk). Distribution. Mediterranean; North and South Atlantic, 35^-34° S; Indian Ocean (one record only from 5 S). Phronima pacifica, Streets. Vosseler, 1901, p. 29; pi. iii, figs. 4-7. Stephensen, 1924, p. 130. Mogk, 1927, p. 140, chart 8. Barnard, 1930, p. 423. Occurrence: 1. St. 87. South-east Atlantic. 1 $ 9 mm. 2. St. 266. South-east Atlantic. 1 $ 7-5 mm. 3. St. 287. East mid- Atlantic. 1 ? 7-5 mm., 1 ovig. $ 9 mm. 2 S6 DISCOVERY REPORTS Remarks. The separation of colletti, Bov., from this species will probably prove im- possible when more material has been examined on the lines pursued by Mogk (1926). Mogk (1927, p. 125) refers to certain transitional specimens, and the present specimens have the dentition on the lower margin of the hand of peraeopod 3 more like that of colletti, though the proportions of the 4th and 5th joints and of the whole limb are those of pacifica. Distribution. Mediterranean; North and South Atlantic, 53 N-9 S; Indo- Pacific. Phronima colletti, Bov. Vosseler, 1901, p. 32; pi. iii, figs. 8-10; pi. iv, figs. 1-3. Stephensen, 1924, p. 127, chart 18. Mogk, 1927, p. 139, chart 7. Occurrence: St. 290. East mid-Atlantic. 1 $ 7 mm. Distribution. Mediterranean; North and South Atlantic, 4i°N-35°S; Indo- Pacific. Genus Phronimella, Claus. Stephensen, 1924, p. 130. Phronimella elongata (Claus). Vosseler, 1901, p. 40, text- fig. Stephensen, 1924, p. 130, chart 19. Mogk, 1927, p. 141, charts 9-1 1. Barnard, 1930, p. 423. Occurrence: 1. St. 2 20' S, 12 45' W. 1 $ 6 mm. in penult, instar, 2 adult <$<$ 7 mm., 10 $? 5-1 1 mm. 2. St. 296. East mid-Atlantic. 1 adult 11-12 mm. 10. St. 120. South Atlantic. 1 <$ 7 mm. 11. St. 151. South Georgia. 2 ?? 8-9 mm. 12. St. 239. South-west Atlantic. 2 ovig. $$ 14 mm. 13. St. 257. South-east Atlantic. 1 cj 8 mm. 14. St. 266. South-east Atlantic. 5 ovig. $$ 7-9 mm. 15. St. 297. East mid-Atlantic. 1 ovig. $ 6 mm. Remarks. In no. 7 the smallest^ is in the penultimate stage, the largest is adult. The process of antenna 1 is considerably longer than in the figures given by Vosseler, and by Chevreux and Fage. At St. 89 and St. 151 other (day) hauls were made in 1275-0 m., including horizontal hauls 0-132 m., and vertical hauls at several levels down to 1000 m., but with negative results as far as this species was concerned. Note 70 for St. 105 states that the blue colouring is due to eggs which are cobalt-blue. The distal joints of peraeopod 3 were missing in the specimen figured. This coloured sketch is reproduced here on PI. I, fig. 8. This appears to be principally a rather deep-water species (500-1000 m. or more) and propagates throughout the year (Stephensen, 1924, p. 145). Ovigerous $? were found in June and July (29°-46° S), August (12 N) and November (44 S) by the ' Discovery'. The present material also appears to afford some evidence that the larger specimens come from the higher latitudes (cf. nos. 3, 8, 9, 12, 14 and 15). Distribution. Mediterranean; Atlantic, 47°N-36°S; Indo-Pacific; Antarctic, 58°-66° S, 85°-8 9 ° E. Genus Anchylomera, M. Edw. Stebbing, 1888, p. 1432. Bovallius, 1889, p. 408. Anchylomera blossevillei, M. Edw. Barnard, 1930, p. 425 (references). Occurrence: 1. St. 101. South-east Atlantic (350-400-0 m.). 1 99 mm. 2. St. 257. South-east Atlantic. 2 $<$ 9 mm. Remarks. The SS show no traces of the metallic sheen. It is curious that there should be so few specimens in the present collection. Distribution. Mediterranean; Atlantic, 43 N-38 S; Indo-Pacific. PRONOIDAE 289 Family PRONOIDAE Stephensen, 1925 a, p. 155. Spandl, 1927, p. 216 (key to genera 1 ). Genus Pronoe, Guer. Stebbing, 1888, p. 1507. Pronoe capito, Guer. Claus, 1887, p. 50, pi. xii, figs. 1-14. Stebbing, 1888, p. 1508, pi. clxxxvi. Spandl, 1924, p. 34, fig.; 1927, p. 217. Pirlot, 1929, p. 147. Occurrence: 1. St. 276. East mid-Atlantic. 4 $? 7-10 mm. 2. St. 288. East mid-Atlantic. 2 $$ 12 mm. 3. St. 294. East mid-Atlantic. 1 $ 10 mm. 4. St. 295. East mid-Atlantic. 1^9 mm. 5. St. 296. East mid- Atlantic. 2 ?? 9-10 mm. (the larger with uterine ova). Distribution. Mediterranean; North Atlantic, o°-32°N; Red Sea and Indian Ocean ; South Pacific. Genus Eupronoe, Claus. Stephensen, 1925 a, p. 156. Spandl, 1927, p. 222. Eupronoe minuta, Claus. (PI. I, fig. 6). Stebbing, 1888, p. 1513 (pacifica juv. $) and p. 1516. Chevreux and Fage, 1925, p. 425, fig. 417. Stephensen, 1925 a, p. 160, figs. 55, 56. Spandl, 1927, p. 223, fig. 41. Occurrence: 1. St. 89. South-east Atlantic. 2 ?$ 6 mm. 2. St. 266. South-east Atlantic. 6 S3 and 2 $$ 6 mm. (1 ? with embryos). Remarks. Although recorded from the South Pacific (south of Australia) this species does not seem to have been caught hitherto in the South Atlantic. Distribution. Mediterranean; North Atlantic about 36°-3i°N.; Canaries and Azores; South Pacific. Eupronoe maculata, Claus. Stebbing, 1888, p. 15 10, pi. clxxxvii (inscripta). Stephensen, 1925 a, p. 156, figs. 53, 54, chart 24. Spandl, 1927, p. 222. Barnard, 1930, p. 426. Occurrence : St. 297. East mid-Atlantic. 1 3 8 mm. Distribution. Mediterranean; Atlantic, 40 N-29 S; Indo-Pacific. 1 Paralycaea omitted. Under 2b 2 "das Telson. . ." refers to Sympronoe, not to Parapronoe; and under I&! and ib 2 the word "ersten" seems to have been omitted before "Pereiopodenpaare". dv 37 2 9 o DISCOVERY REPORTS Genus Parapronoe, Claus. Claus, 1887, p. 53. Stephensen, 1925 a, p. 165. Spandl, 1927, p. 219. Barnard, 1930, p. 427. Parapronoe clausoides, Stebb. (Fig. 165). Stebbing, 1888, p. 1529, pi. cxci. Walker, 1909, p. 54. Stephensen, 1925 a, p. 165 (united with crustulum). Occurrence: St. 296. East mid-Atlantic. 3 $? with embryos 17 mm. Remarks. Identified with clausoides on account of the very conspicuous serration of the 2nd joint of peraeopod 4, as shown in Stebbing's figure; but this serration is stronger and all the denticles except those on the proximal third of the row point towards the base of the joint ; also on account of the elongate process of the 4th joint of same peraeopod, and the two terminal joints of peraeopod 5 . The sides of the telson, however, are evenly Fig- l6 5- Parapronoe clau- convex as in clausi and crustulum, and the lower margin of the so l ' te ' econ 1 J0in . • r 1 ■ ^ f of peraeopod 4, with mar- 5th joint of gnathopod 1 is smooth. All these characters may • f urther enlarged. later be shown to be subject to variation. Distribution. Australia; Indian Ocean. Parapronoe crustulum, Claus. Claus, 1887, p. 55, pi. xv. Stebbing, 1888, p. 1530, pi. cxciii, fig. A. Stephensen, 1925 a, p. 165. Spandl, 1927, p. 220, fig. 39 (stebbingi) and p. 221, fig. 40. Occurrence: 1. St. 276. East mid-Atlantic. 3 ?$ 10-12 mm. 2. St. 285. East mid-Atlantic. 1 ? 13 mm., 3 $$ with embryos 17-18 mm. 3. St. 286. East mid-Atlantic. 1 $ 13 mm. 4. St. 287. East mid-Atlantic. 2 ?$ (1 ovig.) 13 mm., 1 ? 18 mm. 5. St. 290. East mid- Atlantic. 2 $? with embryos 16 and 18 mm. Distribution. Atlantic, 47°-i7° N; Indo-Pacific. Parapronoe campbelli, Stebb. Stebbing, 1888, p. 1522, pi. clxxxix. Chevreux, 1900, p. 152. Barnard, 1930, p. 427. Occurrence: St. 87. South-east Atlantic. 1 $ 10-5 mm. Remarks. This forms the first record of this species from the South Atlantic. Distribution. North Atlantic (Azores); Pacific, 35 N and New Zealand Sea. LYCAEIDAE 291 Genus Sympronoe, Stebb. Stebbing, 1888, p. 1533. Sympronoe parva (Claus). Claus, 1887, p. 55, pi. xiv, figs. 13-18. Stebbing, 1888, p. 1533, pi. cxcii and p. 1537, pi. cxciii, fig. B (propinqua). Shoemaker, 1925, p. 42, figs. 14, 15 (anomala). Stephensen, 1925 a, p. 162, fig. 58; and var. j-articulata, p. 162, figs. 59, 60. Spandl, 1927, p. 225, fig. 43. Occurrence: St. 286. East mid- Atlantic. 1 $ 6 mm., 1 ? 6-5 mm. Remarks. There seems to me no reason for regarding propinqua and anomala as separate species. Shoemaker's species has three terminal joints in peraeopod 5; Stephensen 's var. y-articulata has the full number of joints. Spandl refers to the variability of parva. The present $ has the triangular telson of propinqua and two terminal joints in peraeopod 5. Distribution. Mediterranean; Atlantic, io° N-io° S; Indo-Pacific. Family LYCAEIDAE Chevreux and Fage, 1925, p. 426 (part). Stephensen, 1925 a, p. 167. Spandl, 1927, p. 211 (part). Genus Lycaea, Dana. Chevreux and Fage, 1925, p. 429. Barnard, 1930, p. 428. Lycaea nasuta, Claus. Claus, 1887, p. 62, pi. xviii, figs. 1-7. Barnard, 1930, p. 430, fig. 59. Occurrence: 1. St. 89. South-east Atlantic. 1 ^ 8 mm. 2. St. 286. East mid-Atlantic. 1 ovig. $ 8 mm. Remarks. This species has not hitherto been reported from the Atlantic. The $ is more like a Thamneus in shape, having the head and peraeon twice as broad as in the <$. The projection of the lower distal corner of the 6th joint in gnathopods 1 and 2 is very small, i.e. the distal width is scarcely twice the basal width of the dactylus, which is very short. Dactyls of peraeopods 1-4 very short. Distribution. Zanzibar; New Zealand. 37-2 292 DISCOVERY REPORTS Family BRACHYSCELIDAE Stephensen, 1925 a, p. 171. Genus Brachyscelus, Bate. Stephensen, 1925 a, p. 172. Brachyscelus crusculum, Bate. Stewart, 1913, p. 262. Chevreux and Fage, 1925, p. 427, fig. 418. Stephensen, 1925 a, p. 172, chart 26. Spandl, 1927, p. 210. Occurrence: 1. St. 83. South-east Atlantic. 1 ovig. $ 1 7 ram. 2. St. 89. South-east Atlantic. 3 ovig. $$ 15-16 mm. 3. St. 101. South-east Atlantic (350-400-0 m.). 1 ? 17 mm. 4. St. 257. South-east Atlantic. 1 c? 14 mm. 5. St. 267. South-east Atlantic (450-550-0 m.). 1 c? 17 mm. 6. St. 273. Portuguese West Africa. 4^ 13-14 mm., 5 $? 14-16 mm. (ovig. and with embryos). 7. St. 276. East mid-Atlantic. 2 $<$ 13 mm., 4 $$ 9-14 mm., 1 ovig. $ 16 mm. 8. St. 286. East mid- Atlantic. 1 $ 15 mm. 9. St. 296. East mid-Atlantic. 1 S 15 mm., 1 $ 14 mm., 1 $ 20 mm. Distribution. Mediterranean; Atlantic, 51 N-32 S; North Pacific. Brachyscelus rapax, Claus (PI. I, fig. 7). Claus, 1887, p. 59, pi. xvii, figs. 1-8. Occurrence: St. 25 47' S, 14 48' W. 3 ?? 6-5 mm. Description. Telson apically rounded. Gnathopods 1 and 2, 5th joint without projection overhanging base of 6th joint, distal margin with one tooth, lower margin with three teeth, not including the apical tooth, lower margin in gnathopod 1 in addition finely serrulate, 6th joint with three teeth on inner margin. Peraeopods 1-3, margins of all joints smooth. Peraeopod 4, anterior margin of 4th joint smooth, of 5th and 6th pectinate. Peraeopod 5, 2nd joint pyriform, subequal to the following joints together. Uropod 1, rami longer than peduncle, inner ramus lanceolate, broader than outer ramus. Uropod 2, outer ramus about as long as peduncle, inner ramus considerably longer, ovate lanceolate. Uropod 3, inner ramus considerably longer than outer, ovate lanceolate. Remarks. Note 12 accompanying a coloured sketch from life says: "The brilliant iridescent colouring, produced by the physical properties of the surface, is backed by deeply pigmented chromatophores". Distribution. Cape of Good Hope (Claus). BRACHYSCELIDAE 293 Brachyscelus globiceps (Claus). Claus, 1887, p. 59, pi. xvi, figs. 1, 2, 4-10. Stephensen, 1925 a, p. 176, fig. 65. ? Stebbing, 1888, p. 1555, pi. cxcvii, fig. C (latipes). Occurrence: St. 273. Portuguese West Africa. 1 ? 13 mm. (breadth of head 4-5 mm., of peraeon 5 mm.). Remarks. As regards the telson and uropods this specimen agrees better with Stebbing's figure than with Stephensen 's, the telson being apically rounded, and the outer ramus of uropod 3 four-fifths the length of the inner ramus. The conspicuous scale markings mentioned by Stebbing are not visible, but the integument of the peraeon and pleon is minutely scabrous. I am not quite satisfied that this specimen is correctly identified with Claus' species. Neither Stebbing nor Stephensen make any special mention of the breadth of the head and peraeon, which is particularly noticeable in comparison with crusculum. In fact at a first glance it appears to be a Thomneus, but the 4th-6th joints of peraeopod 4 are regularly pectinate on their margins, and are without the additional setae found in T. platyrhynchns . Distribution. Mediterranean; Zanzibar; South Pacific (latipes). Genus Thamneus, Bov. Stebbing, 1888, p. 1558. Stephensen, 1925 a, p. 180 (Euthamneus). Pirlot, 1929, pp. 152, 153 (Euthamneus). I cannot follow Pirlot in separating Thamneus and Brachyscelus into different families. They appear to me to be intimately related, and Stebbing (1888, p. 1555) considered B. bovallii as in some respects a connecting link between the two genera. With a series of forms like bovallii, globiceps, rapacoides, the difficulty is to find a distinctive character separating the two genera. At first sight it appears that the very regular pectination of the margins of the 4th-6th joints of peraeopod 4 is absent in Thamneus (it is not shown in Stephensen's fig. 70, and only indistinctly in Stebbing's figure, pi. cxcviii), but it is present in the specimen here examined, though nearly obsolete on the 4th joint. The articulation of the telson with the last pleon segment is not a distinguishing feature, as the telson is just as movably articulated in Brachyscelus as in Thamneus. Under the International Nomenclatorial Rules the original name must stand. Thamneus platyrhynchus, Stebb. Stebbing, 1888, p. 1558, pi. cxcviii. Stephensen, 1925 a, p. 180, figs. 69, 70 (Euthamneus p.). Spandl, 1927, p. 210 (Euthamneus p.). Occurrence: St. 281. East mid-Atlantic. 1 $ 7-5 mm. Remarks. Though the types of rostra t us are no longer extant, Stephensen thinks that in all probability this species is the same as Bovallius' species. Distribution. Mediterranean; Atlantic, about 5i°N-5° S; Indo-Pacific; Cape of Good Hope (rostratus). 294 DISCOVERY REPORTS Family OXYCEPHALIDAE Bovallius, 1890. Stephensen, 1925 a, p. 182. Spandl, 1927, p. 178. Stephensen makes Dorycephalus synonymous with Leptocotis ; he retains Rhabdosoma (Xiphocephalus) within the family, and also Simorhynchotus , though the latter, together with Metalycaea and Glossocephalns, form a transition to the Lycaeidae as regards the shape of the head. Spandl, without giving critical reasons, excludes Simorhynchotus from this family and assigns it to the Lycaeidae. Genus Oxycephalus, M. Edw. Bovallius, 1890, p. 54 (key to species). Spandl, 1927, p. 179. Cecchini, 1929, p. 5 (two n.spp.). Oxycephalus clausi, Bov. Bovallius, 1890, p. 60, figs. 4, 7, 8, 22, 54, 65; pi. i, figs. 19-24; pi. ii, fig. 1. Stephensen, 1925 a, p. 188, chart 27. Spandl, 1927, p. 180. Barnard, 1930, p. 433. Occurrence: 1. St. 33 37' N, 14 39' W. 1 % s - 66-69 (aequilibra). Occurrence: St. 34 23' N, 14 32' W. 3 <3<$ 5-8 mm., 1 $with embryos 7 mm., 1 immat. ? 6 mm. Distribution. Widely distributed. Caprella acutifrons, Latr. Mayer, 1903, p. 79, pi. iii, figs. 4-28; pi. vii, figs. 62-65 (references). Stebbing, 1910 a, p. 465 {penantis). Occurrence : St. 4. Tristan da Cunha. Many, $<$ up to 1 1 mm., $$ up to 6 mm., incl. many ovig., with embryos, and juv. Remarks. The S3 have the "poison tooth" of gnathopod 2 proximal and resemble vars. natalensis and porcellio. The tooth varies in size and may be straight or crooked, so there seems little use in keeping the two varieties separate. Distribution. Widely distributed, including Magellan Strait and the Brazilian coast. Genus Pseudaeginella, Mayer. Mayer, 1890, p. 37. Hitherto regarded as a monotypic genus recorded from Tristan da Cunha and Antigua, W.I. For the form from the latter locality, however, a new name is here proposed. Pseudaeginella tristanensis (Stebb.) (Fig. 166). Stebbing, 1888, p. 1249, pi. cxliii. Mayer, 1890, p. 37, pi. v, fig. 51 ; pi. vi, fig. 14. Non Stebbing, 1895 {Ann. Mag. Nat. Hist. (6), xv), p. 397. Non Mayer, 1903, p. 59. Occurrence: St. 4. Tristan da Cunha. 1 $ 4-5 mm., 1 $ (brood pouch empty) 4-5 mm. Fig. 166. Pseudaeginella tristanensis (Stebb.). General view of (J. Remarks. These two specimens taken in the same locality as Stebbing's original specimen may with good reason be assumed to represent the adult form. Possibly the present $ is not fully adult, as it is no bigger than the $, and the hand of gnathopod 2 might be expected to show a more pronounced difference from that of the ?. CAPRELLIDAE 301 Both sexes are alike in the number and arrangement of the dorsal tubercles or spines, which are all single and medio-dorsal. Antenna 1, flagellum n-jointed in both sexes. Antenna 2, flagellum 2-jointed. It might even be called 1 -jointed, because the junction between the two joints is almost obsolete and difficult to trace. The mandibular palp has three spinules between the two larger ones on the apex of the 3rd joint. Gnathopod 2 alike in the two sexes, the "poison tooth" small, acute, slightly beyond the centre of the palm, followed by two small rounded denticles. Peraeopods 3-5 lost in both specimens. In view of these specimens it becomes very unlikely that the specimens (Stebbing says one ; Mayer says two) from Antigua are conspecific. The $ according to Mayer (1903, p. 59) has the head spine and single medio-dorsal spines on segments 1-3, but also paired rounded tubercles in the middle of segments 3 and 4. For this species I therefore propose the name antiguae. Genus Caprellinoides, Stebb. Stebbing, 1888, p. 1237. Mayer, 1890, p. 87; 1903, p. 57. Schellenberg, 1926 a, p. 467. Barnard, 1930, p. 440. The very oblique junction between segments 4 and 5, especially noticeable in the 3, might be incorporated in the generic diagnosis. It is not well shown in Schellenberg's figure of antarctica S, but probably exists as in the other species. Caprellinoides tristanensis, Stebb. Stebbing, 1888, p. 1238, pi. cxli. Mayer, 1890, p. 87. Occurrence: St. MS 14. South Georgia. 1 $ 8 mm. Description of $. Head rounded. Eye composed of nine ocelli. A small medio- dorsal conical tubercle near anterior margin on segment 2, and on middle and posterior margin of segments 3 and 4. Peraeon segment 7 and pleon missing. Antenna 1, flagellum 11 -jointed. Antenna 2, flagellum 3 -jointed. Gnathopod 2 as in Stebbing's figure of the 24, 28 mm., 2 ?$ 20, 21 mm. 5. St. 152. South Georgia. 1 ovig. '+' 21 mm. 6. St. 175. South Shetlands. 1 <^ 23 mm., 1 ovig. $ 25 mm. 7. St. 195. South Shetlands. 3 $<$ 23, 28, 33 mm., 2 ovig. $$ 26, 28 mm., 10 juv. 6-12 mm. Description. Forehead rounded. Eyes distinct, round. Peraeon segment 2 sub- equal to head plus segment 1. Segments 3, 4 and 5 successively longer; segment 6 equal to segment 4. In young specimens up to 12 mm. the body is smooth. The adult 6* has a small lateral tubercle over the base of gnathopod 2 and of the branchiae on segments 3 and 4, a medio-dorsal tubercle on segment 2, and a pair of dorso-lateral tubercles vertically above the lateral ones on segments 3 and 4; the medio-dorsal tubercle on segment 2 absent in ? and sometimes in ^ ; the dorso-lateral tubercles on segments 3 and 4 also are D V 39 3o6 DISCOVERY REPORTS sometimes feeble or obsolete. The dorso-lateral tubercles on the hind margins of seg- ments 2 and 3, present in the Terra Nova $, are here only very feebly developed or quite obsolete. Segment 5 is smooth. A short fine pubescence dorsally on segments 3 and 4 in?. Antenna 1, flagellum 17-18-jointed in j T-> 1 • on the rudimentary pleon it resembles Fig. 171. Cyamusbalaenopterae,Bmrd.a. Dorsal view °" ""' lu J r of .J, with pleon further enlarged, b. Dorsal view of physeteris. The dactyls of peraeopods 5-7 $. c. Ventral view of peraeon segments 5-7 9, with a j so somewhat resemble those of the species just mentioned in their strongly drepani- form curvature. proximal joints of peraeopods 5-7. d. Branchial, e. Gnathopod 1 $. f. Gnathopod 2 , 3 immat. $?, 8 juv. Description. General outline of peraeon in dorsal view ovate in both sexes, the ? not broader than the J. Head and segment 1 completely fused, short, strongly bent downwards. Eyes present (as in other species). Peraeon segment 2 embracing base of segment 1 . Segments 3 and 4 broader than segment 2 (no specimens with these narrower, as in Chevreux and Fage's figure). On ventral surface in $ a pair of blunt inwardly directed processes on segment 5, and a pair of pointed tubercles on both segments 6 and 7; in $ a pair of tubercles on each of segments 5-7; more strongly developed than in $. Antenna 1, 1st and 2nd joints obovate, widening distally. Antenna 2 very small. Gnathopod 1, 5th joint ovate, 6th distally pectinate, unguis distinct. Gnathopod 2, 4th joint prominently projecting on inner (lower) side, apically rounded, 5th with a single strong pointed tooth on inner margin near hinge. Peraeopods 5-7, 2nd joint without projecting apical tubercle on lower surface, 3rd with anterior margin acutely produced, 4th broadly pyriform, distal angles not prominent. Branchiae single on both segments 3 and 4, short and stout, accessory appendages in c? similar to and almost as long as the branchiae themselves, single on each segment, absent in $; at the base of each branchia is a pointed process, directed outwards, in both sexes. Length: £ 6-5 mm., 9 6 mm. Remarks. Both Brandt and Liitken were inclined to regard globicipitis and delphini as synonymous. C. chelipes, Costa, 1866 (Ann. Mns. Napoli., ill, p. 82, pi. iv, fig. 2), also found on a dolphin, appears to be distinct from the present species; but whether it belongs to the genus hocyamiis is impossible to tell, as the description is inadequate. The present species has been recorded from Dolphins and the Black Fish (Globi- cephalus melas) ; also from Grampus griseus and Pseudorca crassidens near the Azores (Chevreux, 1913 a). Fig. 174. Isocyamns delphini (Guer.). a. Dorsal view of (J. b. Gnathopod 1 3- 1906. Amphipoda Gammaridea. Das Tierreich, Lief, xxi, pp. i-xxxix, 1-806, text-figs. 1910. Amphipoda. Scientific Results of the Trawling Expedition of H.M.C.S. 'Thetis' Mem. Austr Mus., iv, pp. 567-658, pis. 47*-6o* (July). 1910 a. General Catalogue of South African Crustacea. Ann. S. Afr. Mus., vi, pt. 4, pp. 281-593, pis. 15-22 (December). 1914. Crustacea from the Falkland Islands collected by Mr Rupert Vallentin, F.L.S. Part II. Proc. Zool. Soc. Lond., 1914, pp. 341-378, pis. 1-9. Stephensen, K., 1915. Isopoda. . .Amphipoda (excl. Hyperiidea). Danish Ocean. Exp. 1908-191010 Mediter- ranean and adjacent seas, 11, D 1, pp. 1-53, text-figs. 1918. Hyperiidea- Amphipoda (Lanceolidae, Scinidae, Vibiliidae, Thaumatopsidae). Dan. Ocean. Exp. 1908-1910, to Mediterranean and adjacent seas, II, D 2, pp. 1-70, text-figs. Note: the title-page states 'Published February 1918', but Stephensen in his ' Ingolf Report, publ. 1923, says on page 5, footnote: 'The "Thor" paper which was finished Oct. 1918 will probably in a short while go to the press'. Also on page 2, ' . . .which will, I hope, be in print next year'. x 9 2 3- Amphipoda I. Danish Ingolf Expedition, in, pt. 8, pp. 1-100, text-figs, and charts. 1924. Hyperiidea- Amphipoda (part 2: Paraphronimidae, Hyperiidae, Dairellidac, Phronimidae, Anchylomeridae). Dan. Ocean. Exp., 1908-1910, to Mediterranean and adjacent seas, 11, D 4, pp. 71-149, text-figs. 1925. Amphipoda II. Danish Ingolf Expedition, in, pt. 9, pp. 101-178, text-figs, and charts (June). 1925 a. Hyperiidea-Amphipoda (part 3 : Lycaeopsidac, Pronoidae, Lycaadae, Bracyliscclidae, Oxy- cephalidae, Parascelidae, Platyscelidae). Dan. Ocean. Exp., 1908-1910, to Mediterranean and adjacent seas, 11, D 5, pp. 150-252, text-figs. (December). 1927. Crustacea from the Auckland and Campbell Islands. Vidensk. Medd. Dansk. naturh. Foren., i.xxxiii, pp. 289-390, text-figs. LITERATURE 319 Stewart, D. A., 1913. A Report on the Extra- Antarctic Amphipoda Hyperiidea collected by the 'Discovery' . Ann. Mag. Nat. Hist. (8), xii, pp. 245-265, pis. 4-7. Strauss, E., 1909. Das Gammaridenauge. Wiss. Ergebn. Deutsch. Tiefsee-Exp. ' Valdivia', xx, pp. 1-84, pis. 1-6, and text-figs. Tattersall, W. M., 1906. Pelagic Amphipoda of the Irish Atlantic Slope. Fisheries, Ireland, Sci. Invest. 1905, iv, pp. 1-39, pis. 1-5. 1922. The Percy Sladcn Trust Expeditions to the Abrolhos Islands {Indian Ocean). Amphipoda and Isopoda. Journ. Linn. Soc. Lond. Zool., xxxv, pp. 1-19, pis. 1-3. Vosseler, J., 1901. Die Amphipoden der Plankton-Expedition, I. Hyperiidea I. Erg. Plankton-Exp., n, G.e. pp. i-viii, 1-129, text-figs, and pis. 1-13. Wagler, E., 1926. Amphipoda 2 : Scinidae. Wiss. Ergebn. Deutsch. Tiefsee-Exp. ' Valdivia ', xx, 6, pp. 3 17- 446, text-figs. 1927. Die Sciniden der Deutschen Siidpolar-Expedition, 1901-1903. Deutsch. Siidpol.-Exp., xix, Zool. xi, pp. 85-m, text-figs. Walker, A. O., 1903. Amphipoda of the 'Southern Cross' Antarctic Expedition. Journ. Linn. Soc. Lond., xxix, pp. 38-64, pis. 7-1 1. 1904. Report on the Amphipoda collected by Professor Herdman, at Ceylon, in 1902. Ceyl. Pearl Oyster Fish. Suppl. Rep., xvn, pp. 229-300, pis. 1-8. 1906. Preliminary description of New Species of Amphipoda from the 'Discovery' Antarctic Expedition, 1902 [«'c]-i904. Ann. Mag. Nat. Hist. (7), xvm, pp. 13-18 and 150-154. 1907. Amphipoda. Nat. Ant. Exp. 1901-1904 ('Discovery'), in, pp. 1-38, pis. 1-13. 1909. Amphipoda Hyperiidea of the ' Sealark' Expedition to the Indian Ocean. Trans. Linn. Soc. Lond. 2 Ser. Zool. xm, 1, pp. 49-55. Woltereck, R., 1903. Bemerkungen zu der Amphipoda Hyperiidea der Deutschen Tief see- Expedition 1. Thaumatopsidae. Zool. Anz., xxv, pp. 447-459, text-figs, and pi. 2. 1904. Zzveite Mitteihtng iiber die Hyperiden der Deutschen Tief see-Expedition. "Physosoma ", ein neuer pelagischer Larventypus, nebst Bemerkungen zur Biologic von Thaumatops und Phronima. Zool. Anz., xxvii, pp. 553-563, text-figs. (17th May). 1904 a - Dritte Mitteihtng iiber die Hyperiden der Deutschen Tief see-Expedition, und Erste Notiz ilber die Amphipoden der Deutschen Siidpolar-Expedition. Zool. Anz., xxvn, pp. 62 1-629, text-figs. (14th June). 1905. Mitteilungen iiber Hyperiden der ' Valdivia' (No. 4), der 'Gauss' (No. 2) und der Schwedischen Siidpolarexpedition. (a) Scypholanceola, eine neue Hyperidengattung mit Reflektororganen. (b) Die Physosoma-Larva der Lanceoliden. Zool. Anz., xxix, pp. 413-417, text-figs. 1906. Fiinfte Mitteilung iiber die Hyperiden der ' Valdivia' -Expedition: Micromimonectes, n.gen. Zool. Anz., xxx, pp. 187-194, text-figs. (15th May). 1906 a. Weitere Mitteilungen iiber Hyperiden der ' Valdivia' (No. 6) und 'Gauss' Expedition (No. 3). Zool. Anz., xxx, pp. 865-869, text-figs. (27th November). 1909. Amphipoda. Die Hyperiidea Gammaroidea. Sci. Res.' Albatross'. Bull. Mus. Com. Zool. Harv., lii, pp. 145-168, pis. 1-8. 1927. Die Lanceoliden und Mimonectiden der Deutschen Siidpolar-Expedition, 1901-1903. Deutsch. Siidpol.-Exp., xix, Zool. xi, pp. 57-84, text-figs. The following papers were received too late to be consulted : Pirlot, J. M., 1931. Metalanceola chevreuxi, genre et espece nouveaux d'Amphipodes Hyperides. Bull. Inst. Ocean. Monaco, No. 572, pp. 1-14, 3 figs. (May). Schellenberg, A., 193 1. Gammariden und Caprelliden des Magellangebietes , Sudgeorgiens und der West- antarktis. Further Zool. Res. Swed. Ant. Exp., 1901-1903, 11, 6, pp. 1-290, text-figs. 1-136, pi. 1 (March). Stephensen, K., 193 1. Amphipoda. Res. Sci. Ind. Orient. Neerland., in, 4, pp. 1-14, 3 text-figs. (Mem. Mus. Roy. d'Hist. Nat. Belg.) (31st January). 1931 a. Crustacea Malacostraca, vn (Amphipoda, m). Dan. Ingolf Exp., ill, 11, pp. 177-290, text- figs, and charts (24th February). INDEX abyssi, Andaniexis, 77 abyssoides, Pardalisca, 133 abyssorum, Orchomenella, 69 Acanthonotozomatidae, 115 Acanthonotozomella, 117 acanthurus, Epimeria, 176 acanthurus, Orchomenella, 73 Acidostomella, 32 Acontiostoma, 32 acutifrons, Caprella, 300 adarei, Tryphosa, 51 Aeginoides, 305 aequilibria, Caprella, 300 aestiva, Lanceola, 255 afer, Lemboides, 222 affinis, Scina uncipes, 260 albina, Tryphosella, 48 alicei, Cyphocaris, 36 Allogaussia, 64 Allorchestes, 220 Amaryllis, 34 Ambasiopsis, 44 Ampelisca, 81 Ampeliscidae, 81 Amphilochidae, 104 Ampithoe, 239 Ampithoidae, 239 analogica, Tryphosa, 52 anaticauda, Syrrhoites, 151 Anchiphimedia, 123 Anchylomera, 288 Anchylomeridae , 287 Andaniexis, 76 Andaniotes, 80 anguipes, Ischyrocerus, 243 anomala, Aora typica, 220 anomala, Sympronoe, 291 anonyx, Cyphocaris, 36 anonyx, Cyphocaris, 35 antarctica, Byblis, 85 antarctica, Gitanopsis, 104 antarctica, Hyperia, 273 antarctica, Hyperiella, 275 antarctica, Leucothoe, 106 antarctica, Melphidippa, 188 antarctica, Polycheria, 217 antarctica, Pontogeneia, 199 antarctica, Rhachotropis, 194 antarctica, Seba, 107 antarctica, Themisto, 280 antarctica, Vibilia, 263 antarcticum, Pachychelium, 75 antarcticus, Aristias, 43 antarcticus, Cyllopus, 266 antarcticus, Eusirus, 188 antarcticus, Monoculodes, 136 [Synonyms are indicated by italics.] antarcticus, Proboloides, no antarcticus, Tiron, 148 antennipotens , Tryphosa, 47 Aora, 220 Aoridae, 220 Apherusa, 198 Archaeoscinidae , 250 Argissidae, 145 Aristias, 43 armata, Vibilia, 264 armatum, Rhabdosoma, 297 armatus, Platyscelus, 298 ascensionis, Maera, 214 assimilis, Aty hides, 209 Astropleustes, 168 atlantica, Phronima, 285 atlantica, Stenopleura, 161 Atylidae, 183 Atyloella, 201 Atyloides, 203, 204 Aty liis, 159 australis, Andaniexis, 76 australis, Vibilia, 264 austrina, Paramoera, 206, 209 Austronisimus, 37 Austropleustes, 168 balaenopterae, Cyamus, 309 barbimanus, Haplocheira, 235 batei, Atylus, 159 bidentata, Oradarea, 165 bidentata, Paramoera, 210 bispinosa, Parathemisto, 280 blaisus, Megamphopus, 233 blossevillei, Anchylomera, 288 boecki, Parandania, 77 bonellii, Corophium, 244 boopis, Paracyamus, 312 borealis, Scina, 260 bouvieri, Ampelisca, 82 bouvieri, Eusirus, 188 Bovallia, 196 Bovallia, 161 Brachyscelidae, 292 Brachyscelus, 292 bransfieldi, Ampelisca, 83 bransfieldi, Iphimediella, 119 brasiliensis, Ampithoe, 240 brasiliensis, Podocerus, 246 brasieri, Colomastix, 114 brevicornis, Ampelisca, 84 brevicornis, Pontogeneiella, 200 brevimanus, Paraperioculodes, 135 brevipes, Ampithoe, 239 Byblis, 85 Byblisoides, 86 41 322 Cacao, 152 Calliopiidae, 155 Calliopius, 198 calmani, Oediceroides, 140 campbelli, Parapronoe, 290 capensis, Liljeborgia kinahani, var., 142 capensis, Paramoera, 209 capensis, Phylluropus, 146 capicola, Iphimedia, 118 capito, Pronoe, 289 Caprella, 300 Caprellidae, 299 Caprellinoides, 301 Cardenio, 90 carinata, Proboloides, no carinata, Tmetonyx, 55 cariniceps, Harpinia, 99 castellata, Colomastix, 1 1 5 castellata, Tryphosa, 53 cavimanus, Orchomenella, 69 Cerapus, 245 cetrata, Lepechinella, 186 challenged, Cyphocaris, 36 challenged, Streetsia, 295 charcoti, Orchomenella, 70 Cheirimedon, 47 chelata, Clarencia, 156 chevreusi, Parascina, 253 chevreuxi, Tryphosites, 54 Chosroes, 157 cingulatum, Lepidepecreum, 60 Clarencia, 155 clausi, Oxycephalus, 294 clausoides, Parapronoe, 290 clypeata, Paraphronima, 267 coatsi, Pseudorchomene, 74 colletti, Phronima, 286 collinus, Aristias, 44 Colomastigidae, 114 Colomastix, 114 compressa, Parathemisto, 280 Corophiidae, 244 Corophium, 244 coxalis, Phoxocephalus, 97 crassicornis, Scina, 258 crassipes, Paraphronima, 267 crassipes, Scina, 261 crenatipalmatus, Proboloides, in crenulata, Parepimeria, 179 crusculum, Brachyscelus, 292 crustulum, Parapronoe, 290 cuivis, Paraphronima, 267 cultricauda, Thaumatelson, 113 cultrifera, Acidostomella, 32 cultripes, Vibilia, 265 curvidactyla, Scina, 259 curvipes, Phronima, 285 cuspidatus, Austropleustes, 168 Cyamidae, 307 CYAMIDEA, 299 Cyamus, 307 INDEX cylindricum, Corophium, 244 Cyllopus, 266 Cyphocaris, 34 Cystisoma, 268 Cystisomatidae, 268 Dairella, 282 Dairellidae, 282 danae, Thyropus, 299 danai, Pontogeneia, 198 davidis, Pachychelium, 75 decoratus, Chosroes, 158 delphini, Isocyamus, 313 dentata, Atyloella, 202 dentimanus, Cheirimedon, 48 Dexaminidae, 217 Didymochelia, 247 dilatata, Hyperiella, 274 dimorphus, Eurystheus, 224 diploops, Rhachotropis, 194 distichon, Eurystheus, 227 Djerboa, 203 Dodecas, 303 Dodecasella, 304 Dorbanella, 186 dorsalis, Anchiphimedia, 123 Dorycephalus, 296 dubia, Seba, 106 dubius, Platyscelus, 298 echinata, Echiniphimedia, 126 echinata, Iphimediellia, 119 Echiniphimedia, 125 Eclysis, 181 edentata, Oradarea, 167 edouardi, Paramoera, 407 elegans, Dodecasella, 304 elegans, Eusirella, 194 elephantis, Podoceropsis, 234 elongata, Phronimella, 286 Epimeria, 170 Epimeriella, 178 Epimeriopsis, 182 epistomata, Liljeborgia, 144 equilibra, Caprella, 300 erraticus, Paracyamus, 310 eschrichtii, Ampelisca, 81 Euandania, 80 Eumimonectidae, 252 Euprimno macropus, 287 Eupronoe, 289 Eurymera, 197 eurypodii, Eurystheus, 231 Euryporeia, 58 Eurystheus, 224 Eurythenes, 58 Eusirella, 194 Eusiridae, 188 Eusiroides, 191 Eusirus, 188 INDEX 323 Eathamneiis, 293 Euthetnisto, 280 excisa, Panoploea, 129 excisipes, Epimeria, 174 fabricii, Cystisoma, 272 falcata, Jassa, 241 falcata, Urothoe, 91 falklandica, Liljeborgia kinahani, var., 142 falklandica, Lysianassa, 39 faurei, Cyphocaris, 36 femoratus, Cheirimedon, 48 fissicauda, Paradexamine, 217 fissicaada, Paramoera, 209 fissilingua, Colomastix, 114 fowled, Parascina, 252 fowleri, Parascina, 253 fresnelii, Melita, 21 1 fuegiensis, Lembos, 221 furcipes, Djerboa, 203 galba, Hyperia, 273 galba, Hyperia, 273 Gammaridae, 211 GAMMARIDEA, 28 gaudichaudii , Hyperia, 273 gaudichaudii, Parathemisto, 280 gaussi, Aeginoides, 305 gaussi, Pseuderichthonius, 245 genarum, Pagetina, 131 georgensis, Ambasiopsis, 44 georgensis, Liljeborgia kinahani, var., 142 georgiana, Parajassa, 243 georgiana, Pontogeneia, 198 georgianus, Eusiroides, 191 gibbula, Aora typica, var., 220 gigantea, Bovallia, 196 gigantea, Euandania, 80 gigas, Uristes, 47 Gitanopsis, 104 globiceps, Brachyscelus, 293 globicipitis, Isocyamus, 314 Gnathiphimedia, 121 goniamera, Jassa, 242 gracilis, Paracyamus, 312 gracilis, Paraphronima, 267 gracilis, Prostebbingia, 201 gracilis, Schraderia, 204 grandicornis, Vibilia, 265 grata, Piper el la, 302 gregaria, Paramoera, 206 Halice, 134 Halirages, 159 Haplocheira, 235 Haploops, 88 Harpinia, 99 Haustoriella, 94 Haustoriidae, 90 helgae, Metacyphocaris, 37 hemicryptops, Ampelisca, 83 Hemityphis, 298 hermitensis, Paramoera, 208 Heterophoxus, 100 hodgsoni, Echiniphimedia, 125 Hoplopleon, 105 huxleyanus, Halirages, 159 huxleyanus, Abyhis, 159 Hyale, 219 Hyalella, 219 hypacanthus, Lembos, 221 Hyperia, 273 Hyperiella, 274 Hyperiidae, 273 HYPERIIDEA, 249 Hyperioides, 275 Hyperoche, 276 hystricoides, Podocerus, 246 impressicauda, Oradarea, 166 inaequistylis, Melita, 212 incerta, Scina, 260 incisus, Chosroes, 157 inermis, Epimeria, 173 inermis, Platyscelus, 298 inermis, Thaumatelson, 112 ingens, Jassa, 242 inscripta, Eupronoe, 289 insigne, Stomacontion, 33 integricauda, Pariphimedia, 127 intermedia, Epimeria, 177 intermedia, Streetsia, 295 Iphimedia, 118 Iphimediella, 119 irene, Micromimonectes, 250 Ischyrocerus, 243 Isocyamus, 313 Jassa, 241 Jassidae, 241 joubini, Panoploea, 128 juxtacornis, Byblisoides, 87 Katius, 55 kergueleni, Tryphosa, 49 Kerguelenia, 28 kinahani, Liljeborgia, 142 Kuphocheira, 237 Labriphimedia, 123 lacteus, Cacao, 153 lahillei, Oediceroides, 140 Lanceola, 253 Lanceolidae, 253 langhansi, Scina, 260 laticarpus, Eusirus, 188 latipes, Brachyscelus, 293 latipes, Scina, 261 latissima, Dairella, 282 Lemboides, 222 41-2 324 Lembos, 221 Lepechinella, 186 Lepechinellidae, 186 Lepidepecreella, 61 Lepidepecreoides, 62 Lepidepecreum, 60 Leptamphopiis, 163 Leptocotis, 296 Leucothoe, 105 Leucothoidae, 105 Liljeborgia, 142 Liljeborgiidae, 142 lindstromi, Dorycephalus, 296 linearis, Andaniotes, 80 Liouvillea, 152 lobata, Allogaussia, 67 longkaudata, Photis, 223 longicornis, Liljeborgia, 143 longicornis, Pontogeneiella, 200 longimana, Oradarea, 165 longimanus, Ischyrocerus anguipes, var., 243 longipes, Hyperioides, 276 longitelson, Tmetonyx, 54 lucasii, Cyllopus, 266 Lycaea, 291 Lycaeidae, 291 Lysianassa, 39 Lysianassidae, 28 macrocephala, Ampelisca, 82 macrocystidis, Panoploea, 128 macrodactylus, Oediceroides, 141 macrodonta, Epimeria, 172 macronyx, Epimeriella, 178 macronyx, Mimonecteola, 251 macronyx, Orchomenella, 70 macronyx, Synopioides, 134 macropa, Primno, 287 macrophthalma, Amaryllis, 34 macrops, Gnathiphimedia, 122 macropus, Euprimno, 287 macrura, Melphidippa, 188 maculata, Eupronoe, 289 Maera, 212 magellanica, Atyloella, 201 magellanica, Pontogeneia, 207 magellanicum, Acontiostoma, 32 magellanicus, Cyllopus, 266 magellanicus, Eurythenes, 59 major, Parepimeria, 180 major, Tryphosa, 50 mandibularis, Gnathiphimedia, 121 marginata, Scina, 261 margueritei, Iphimediella, 119 marionis, Acontiostoma, 32 mayeri, Caprellinoides, 302 medusarum, Hoplopleon, 105 medusarum, Hyperoche, 276 Megamphopus, 232 Melita, 211 INDEX Melphidippa, 188 Melphidippidae, 188 Metacyphocaris, 37 Methalimedon, 141 Metopella, 108 Metopidae, 108 Metopoides, 108 Micromimonectes, 250 Micromimonectidae, 250 micronyx, Cyphocaris, 36 microps, Eusirus, 191 miersii, Paraceradocus, 215 Mimonecteola, 251 Mimonectidae, 252 minuta, Eupronoe, 289 miothele, Parepimeria crenulata, var., 180 Monoculodes, 136 monoculoides, Bovallia, 196 monticulosa, Eurymera, 198 nasuta, Lycaea, 291 nasutum, Thaumatelson, 112 navicula, Allogaussia, 65 Nicippe, 133 nodosa, Echiniphimedia, 126 nodosa, Iphimediella, 119 nodulosa, Syrrhoe, 150 nordenskjoldii, Methalimedon, 141 normani, Pariphimedia, 127 Nototropis, 183 novae-zealandiae, Leptamphopiis, 163, 165, 167 oatesi, Acanthonotozomella, 117 obesa, Waldeckia, 43 obesus, Katius, 56 obliqua, Parharpinia, 101 obliquimanus, Paramoera, 208 obiusifrons, Heterophoxus, 100 oculata, Liouvillea, 152 odhneri, Paralysianopsis, 38 oedicarpus, Scina, 261 Oediceroides, 140 Oedicerotidae, 135 onconotus, Tryphosa, 53 oniscoides, Urothoides, 93 oppositus, Cerapus, 245 Oradarea, 162 Orchestia, 218 Orchomenella, 68 Orchomenopsis , 68, 70, 74 ovalis, Cyamus, 307 ovalis, Lepidecreella, 61 ovata, Metopella, 108 ovoides, Platyscelus, 297' Oxycephalidae, 294 Oxycephalus, 294 Pachychelium, 75 pacifica, Eupronoe, 289 pacifica, Gnathiphimedia, 122 INDEX 32S pacifica, Lanceola, 255 pacifica, Paradexamine, 217 pacifica, Phronima, 285 pacifica, Scina, 261 pacificus, Paracyamus, 312 Pagetina, 131 Pagetinidae, 131 palmata, Ampelisca, 85 palmoides, Eurystheus, 231 palpalis, Kerguelenia, 28 Panoploea, 128 Paraceradocus, 215 Paracyamus, 310 Paradexamine, 217 Parahyperia, 275 Parajassa, 243 parallelocheir, Metopoides, 108 Paralysianopsis, 37 Paramoera, 206 Paramphithoidae, 170 Parandania, 77 Paraperioculodes, 135 Paraphronima, 267 Paraphronimidae, 267 Parapronoe, 290 Parascelidae, 299 Parascelus, 299 Parascina, 252 Parathemisto, 280 Pardalisca, 133 Pardaliscidae, 133 Parepimeria, 179 Parhalimedon, 141 Parharpinia, 101 Pariphimedia, 126 parva, Sympronoe, 291 patagonica, Hyalella, 219 patagonkus, Allorchestes, 220 paurodactylus, Cardenio, 91 Pegohyperia, 276 pellucidum, Cystisoma, 272 penantis, Caprella, 300 perdentatus, Eusirus, 189 pfefferi, Maera, 212 Phippsiella, 76 Photidae, 223 Photis, 223 Phoxocephalidae, 97 Phoxocephalopsis, 94 Phoxocephalus, 97 Phronima, 282 Phronimella, 286 Phronimidae, 282 Phrosina, 287 Phrosinidae, 287 Phylluropus, 145 piscator, Oxycephalic, 294 platensis, Orchestia, 218 platyrhynchus, Thamneus, 293 Platyscelidae, 297 Platyscelus, 297 Pleustidae, 168 Podoceridae, 246 Podoceropsis, 234 Podocerus, 246 Polycheria, 217 Pontogeneia, 198 Pontogeneiella, 200 Pontogeneiidae, 195 porcellanus, Proboloides, 1 1 1 porcellus, Streetsia, 295 Primno, 287 princeps, Pegohyperia, 276 Proboloides, 108 profundi, Halice, 134 Pronoe, 289 Pronoidae, 289 propinqua, Sympronoe, 291 propinqua, Vibilia, 263 propinqua, Vibilia, 263 propinquus, Eusirus, 188 Prostebbingia, 201 psammophila, Haustoriella, 95 Pseudaeginella, 300 Pseuderichthonius, 245 Pseudorchomene, 74 psychrophila, Syrrhoe, 149 pulchella, Jassa, 241 puncticulata, Epimeria, 175 purpurescens, Eurystheus, 226 pusilla, Colomastix, 114 pusilla, Jassa, 242 pyripes, Vibilia, 265 rapax, Brachyscelus, 292 rapax, Hemityphis, 298 rattrayi, Scina, 261 reducta, Dodecas, 303 regis, Halirages, 161 remipes, Eurystheus, 229 remipes, Lanceola, 255 Rhabdosoma, 296 Rhachotropis, 194 rhinoceros, Austronisimus, 38 richardi, Cyphocaris, 35 richardi, Cyphocaris, 36 richardi, Scypholanceola, 257 robusta, Haplocheira, 235 robusta, Lanceola pacifica, var., 255 robusta, Shackletonia, 29 rossi, Orchomenella, 69 rostrata, Phippsiella, 76 rotundifrons, Orchomenella, 72 rotundifrons, Parharpinia, 104 saundersii, Seba, 106 sayana, Lanceola, 254 scabriculosus, Monoculodes, 138 Schraderia, 203 Scina, 258 326 Scinidae, 258 scutigerula, Talorchestia, 218 Scypholanceola, 257 Seba, 106 Sebidae, 106 securiger, Haplodps, 88 sedentaria, Phronima, 283 semilunata, Phrosina, 287 septem-articulata, Sympronoe parva, var., 291 septemcarinatus, Podocerus, 246 serrata, Lanceola, 254 serrata, Tryphosa, 52 serraticauda, Schraderia, 204 serratulus, Platyscelus, 298 serratus, Platyscelus, 298 serricrus, Eurystheus, 228 setimanus, Kuphocheira, 238 sexdentata, Gnathiphimedia, 122 Shackletonia, 29 similis, Eclysis, 182 similis, Epimeria macrodonta, 172 simplex, Austropleustes, 169 simplex, Pontogeneia, 198 sinuata, Parharpinia, 103 Socarnoides, 41 sphaeroma, Thyropus, 299 Sphaeromimonectes, 252 spinicarpa, Leucothoe, 106 spinigera, Hyperia, 273 spinosa, Scina uncipes, forma, 260 splendidus, Eusirus, 189 spongicola, Didymochelia, 248 squamosus, Amphilochiis , 104 statenensis, Ampelisca, 84 stebbingi, Parapronoe, 290 Stebbingia, 206 steenstrupi, Streetsia, 296 Stegocephalidae, 76 Stenopleura, 161 stenopleura, Eusiroides, 192 Stenothoe, 113 Stenothoidae, 113 Stomacontion, 33 Streetsia, 295 subchelata, Melita, 211 submarginata, Scina, 261 Sympronoe, 291 Synopioides, 134 Syrrhoe, 149 Syrrhoites, 151 Talitridae, 218 Talorchestia, 218 tenuimanus, Hemityphis, 298 tenuirostris, Leptocotis, 296 Thamneus, 293 Thaumatelson, 112 Thaumatops, 268 INDEX Themisto, 280 Thyropidae, 299 Thyropus, 299 Tiron, 148 Tironidae, 148 Tmetonyx, 54 triangularis, Tryphosa, 51 tricarinata, Oradarea, 166 trichosus, Heterophoxus, 100 tridentata, Oradarea, 163 tristanensis, Caprellinoides, 301 tristanensis, Parajassa, 243 tristanensis, Paramoera, 209 tristanensis, Pontogeneia, 199 tristanensis, Pseudaeginella, 300 tristensis, Orchestia, 218 Tryphosa, 49 Tryphosella, 48 Tryphosites, 54 tullbergi, Scina, 261 turqueti, Parhalimedon, 141 typhoides, Parascelus, 299 typica, Aora, 220 typica, Proboloides, 108 uncinata, Ambasiopsis, 46 uncinata, Photis, 223 uncipes, Scina, 260 unidentata, Nicippe, 133 Uristes, 47 Urothoe, 91 Urothoides, 92 valdiviae, Eusirella, 194 vallentini, Monoculodes, 139 vanhoeffeni, Scypholanceola, 257 variegata, Lysianassa, 39 vespuccii, Labriphimedia, 124 viatrix, Vibilia, 262 Vibilia, 262 Vibiliidae, 262 videns, Heterophoxus, 100 Vijaya, 34 villosus, Nototropis, 184 vosseleri, Scina, 262 Waldeckia, 43 walkeri, Epimeriella, 178 walkeri, Paramoera, 206 wandeli, Jassa, 242 whitei, Rhabdosoma, 296 wolterecki, Scina, 261 xenopus, Lepidepecreoides, 62 zimmeri, Phoxocephalopsis, 95 zschauii, Orchomenella, 73 zschauii, Waldeckia, 43 PLATE I Coloured figures of Amphipoda made from living specimens on board the R.R.S. 'Discovery' and R.R.S. 'William Scoresby'. Figs, i, 3-8, A. C. Hardy pinx.; Fig. 2, E. R. Gunther pinx. Fig. i. Katius obesus, Chevr., from St. 101 : x 3. Fig. 2. Epimeria acanthurus, Schell., from St. WS 85: x 8. Fig. 3. Epimeriella macronyx, Wlkr., from St. 162: x 4. Fig. 4. Eusiroides stenopleura, n.sp., from St. 114: x 3. Fig. 5. Pegohyperia princeps, Brnrd., from St. 85: x 3. Fig. 5a. Pegohyperia princeps, Brnrd., from St. 85 : front view of head x 3 . Fig. 6. Eupronoe minuta, Claus, from St. 266: x 16. Fig. 7. Brachyscelus rapax, Claus, from 25 47' S, 14 48' W: x 12-5. Fig. 8. Primno macropa, Guer., from St. 105: x 7. DISCOVERY REPORTS, VOL. V. PLATE I. IOHN BALI AMPHIPODA. [Discovery Reports. Vol. V, pp. 327-362, text-figs. 1-10, September, 1932.] THE VASCULAR NETWORKS (RETIA MIRABILIA) OF THE FIN WHALE (BALAENOPTERA PHY S ALUS) By F. D. OMMANNEY, A.R.C.S., B.Sc. CONTENTS Introduction P a S e 3 2 9 The Thoracic Rete 33 1 Appearance of the rete 33 1 Position and relation to muscles .... 33 2 Relation to blood vessels 33° Relation to nerves 34° Summary 347 The Basicranial Rete 34 8 Relation to skull 34 8 Relation to muscles 35° Relation to blood vessels 35 J Relation to nerves 353 Summary 353 The Inguinal Plexus 353 Summary 35° Discussion 35° Summary 3 01 List of Literature 3 02 THE VASCULAR NETWORKS (RETIA MIRABILIA) OF THE FIN WHALE (BALAENOPTERA PHY S ALUS) By F. D. Ommanney, A.R.C.S., B.Sc. (Text-figs, i-io) INTRODUCTION Vascular networks lining the thorax of Cetacea were mentioned by Hunter (1787, pp. 371-450) who wrote of them as follows: "The general structure of the arteries resembles that of other mammals and where parts are nearly similar their distribution is likewise similar. The aorta forms its usual curve and sends off the carotid and sub- clavian arteries. Animals of this tribe, as has been observed, have a greater proportion of blood than any other known and there are many arteries apparently intended as reservoirs where a large quantity of arterial blood seemed to be required in a part and vascularity could not be the only object. Thus we find the intercostal arteries divide into a great number of branches in a serpentine course between the pleural ribs and their muscles — making a thick substance similar to that formed by the spermatic artery in the bull". "These vessels, everywhere lining the sides of the thorax, pass in between the ribs near their articulation and also behind the ligamentous attachments of the ribs and anastomose with each other. The medulla spinalis is surrounded with a network of arteries in the same manner, more especially where it comes out from the brain, where a thick substance is formed by their ramifications and convolutions, and these vessels most probably anastomose with those of the thorax." Since Hunter's time these vascular networks have been noticed by many anatomists. Breschet (1836) described at some length a mass of vessels in the thorax of Delphinus (= Phocaena) phocaena. " II existe sur l'un et l'autre cote de la colonne rachidienne au-devant des cotes, derriere les plevres, depuis le sommet jusqu'a la base de la poitrine, au-dessus du diaphragme, un vaste plexus vasculaire, auquel nous devons, d'apres sa disposition, reconnaitre trois faces, trois bords et trois extremites." Breschet noticed that intercostal nerves, sympathetic branches and ganglia were in connection with the plexus. This author states definitely that the plexus is arterial in constitution. "In all the intrathoracic part of the plexus veins are not discernible except as rare and small branches." He continues: "From the posterior part of the plexus a number of pro- longations penetrate to the neural canal and form a plexus on the posterior part of the spinal ' marrow ' comparable to the spinal plexus in man — except that in man the plexus is essentially formed by veins while in whales it is almost all artery". 33© DISCOVERY REPORTS Stannius (1841) mentioned the network only very briefly in the course of a description of the arteries of Phocaena phocaena. Carte and Macalister (1868) noted the plexus in Balaenoptera rostrata (= B. acuto- rostrata). They found it mainly in the cervical region, within the rings formed by the transverse apophyses of the cervical vertebrae. It reached behind as far as the fourth dorsal vertebra. They noted that the plexus sent prolongations into the neural canal. Owen (1868), who gave to the networks the name "Retia Mirabilia", in his Com- parative Anatomy of the Vertebrates described the rete in the porpoise as an "arterial structure, formed chiefly by the intercostal arteries, lining the sides of the thorax from the ninth and tenth pairs of ribs forwards, penetrating between the ribs near their joints and behind the costal ligaments and there anastomosing with corresponding productions from contiguous intercostal spaces; branches pass therefrom into the neural canal surrounding the myelon with a similar plexus increasing in thickness near the skull and about the macromyelon, anastomosing freely with the myelonal meningeal arteries". Owen also mentioned a similar arterial plexus in the Piked Whale {Balaenoptera acutorostrata) to which the internal mammary arteries also contribute. Turner (1872) mentioned the rete briefly in his description of the Blue Whale dissected by him, and noted that the plexus was not confined to the thorax but extended also into the neck and that prolongations were traceable into the spinal canal. Murie (1873) described various plexuses in the Ca'aing Whale (Globicephala melaena). He mentioned a large network on the basis cranii from the tympanic bone forwards to the maxillary and in the infundibular cavity of the mandible, and another at the root of the Eustachian tube with capillaries connecting into a jugular channel. Mention was also made of a deep lumbar plexus, described also by Owen in the porpoise, underlying the lumbo-caudal muscles and "communicating with the two immense veins lying on either side of the spinal cord". The plexuses, according to Murie, are essentially composed of both arteries and veins. An excellent description of the rete mirabile of the Narwhal was given by Wilson (1879). This author gave some description of the relation of the organ to the nerves of the cervical and thoracic regions and was of the opinion that it is both venous and arterial in constitution. Bouvier (1889), after summarizing the observations of Turner, Owen and Carte and Macalister, proceeded to a description of the plexus in the dolphin (Delphinus delphis). The intercostals, of which there are fifteen pairs, are all (except the first two pairs) given off separately by unpaired trunks from the aorta. These are long in front and short behind. Each bifurcates to give the corresponding intercostals. The two anterior pairs of intercostals are given off by the thoracic arteries. The first intercostal of the succeeding aortic series forms a plexus which is extraordinarily thick at the anterior extremity of the thoracic cavity. Behind, it becomes very narrow and thin. Bouvier also described and figured the plexus in Balaenoptera rostrata. He observed that the arteries outside the plexus, but still very close to it, manifest a tendency to plexus disposition. They give off minute arterioles which anastomose together and come into relation with the plexus THE THORACIC RETE 33 i itself. In B. rostrata and in all Mystacocetes, according to Bouvier, the plexus is formed by intercostals given off from the thoracic artery. The anterior of these breaks up entirely to form the plexus, while the more posterior ones do not, but send branches outside it towards the region of the mammary artery. Bouvier had convinced himself by dissection and injection that the plexus is arterial. Breschet and Owen were also emphatic in their statement of its arterial constitution. Murie, as has been mentioned, considered that it is made up of both arterial and venous components. Carte and Macalister, however, were definitely of the opinion that the plexus is mainly venous. THE THORACIC RETE In order to make clear the structure and relationships of the vascular masses designated the "Rete Mirabile" by Owen, two Fin Whale foetuses were dissected at South Georgia — one o-86 metre (male) and the other 173 metres (female). The major part of the dissection was carried out on the larger of these. However, many of the blood vessels included in the following description, as well as the nerves in the neck region, were made out only in the smaller foetus, since the other had to be decapitated before it could be transported across to the laboratory from the whaling factory. APPEARANCE OF THE RETE During the dismemberment of the adult carcass on the flensing plan, the rete can be seen as a series of fatty masses between the transverse processes of all the cervical and the first six dorsal vertebrae. These fatty masses contain, embedded within their substance, very numerous small thick- walled blood vessels. There can also be seen in the centre of each mass a large vessel which has thin walls and is evidently venous — it passes through the mass from the direction of the spinal cord. These large veins, when opened with a knife, are found to receive numerous small vessels on all sides from the substance of the fatty mass of the rete. In the smaller of the two foetuses dissected the fineness of the component threads of the rete gave the organ the appearance of a diffuse gland, pink in colour and fairly compact and dense in texture, immediately anterior to the thoracic cavity. In the larger foetus it was seen quite clearly to be made up of a mass of minute blood vessels of capillary size. The network enclosed very numerous fine nerve fibres in its meshes. It was seen to be everywhere quite independent of surrounding muscles, but lay in more intimate contact with the anterior two pairs of intercostals, as will be pointed out later in this paper. It was invested by its own thin connective tissue integument and could be easily dissected away from neighbouring tissues. Wherever an artery passed through it, many smaller branches could be seen running from that vessel into the rete, and similarly minute veins were seen running into the venous channels on whose course the rete lay. In many places special retial arteries and veins extended 332 DISCOVERY REPORTS outwards from the major vessels to various parts of the retial mass. Nowhere, how- ever, was the free flow of blood through any part of the thoracic vascular system, arterial or venous, in any way impeded by the anastomosing strands of the rete. The rete communicated freely with the blood vessels with which it stood in relation, but did not form an integral part of them. Wilson (1879) in describing the thoracic rete of the Narwhal distinguished three types of constituent vessels : Vasa maxima — vessels of large calibre with thin puckered walls. These were mainly situated in the inferior aspect of the rete towards its posterior extent. Vasa media — smaller in calibre than the vasa maxima and more generally distributed throughout the mass. The walls of these were also puckered. Vasa minima — much smaller than the preceding with proportionately thick walls. They were found deeply embedded in the rete. In the Fin Whale it was not possible to divide the constituent vessels of the rete into three such definite classes: indeed, Wilson stated that intermediate sizes between the three named were found also in the Narwhal. However, in the Fin Whale large venous channels with thin walls were certainly found running through the substance of the mass and these, as will be seen later, tended to converge towards the posterior thoracic vein and thus lay somewhat posterior and inferior in position. These perhaps were the vasa maxima of Wilson. Secondary smaller venous twigs were also seen which may correspond to the vasa media and the main mass of the retia was made up of much smaller vessels with thick walls which may be looked upon as vasa minima. There were, however, an infinity of gradations between the three sizes. The sinuosities of the component vessels of the retia were much too complicated to unravel by dissection. POSITION AND RELATION TO MUSCLES Some account of the anatomy of the ventral aspect of the neck must be given in order to explain the positions of the various parts of the rete and their relationships. The arrangement of the muscles of the neck was found to be the same as that described by Schulte for the Sei Whale (Balaenoptera borealis). Schulte says (p. 425) : " In the neck a great muscle complex is formed. . . . The complex is of great size and extends its insertion far upon the basis cranii as well as its origin upon the ribs and spine. From these two sources the fasciculi converge and unite inside the arch of the first rib thus extending as a single mass" — on each side — "to the skull. So that the whole complex has the form of an inverted Y" — on each side — "the diverging arms of which embrace the dome of the pleura and limit its extension rostrad" (Fig. 1). The lateral arm of the Y is the scalene muscle and arises chiefly from the external surfaces of the first three ribs and also in part from the fourth and fifth (Fig. 1). The mesial arm of the Y is divisible into a massive "superficial portion extending from the thoracic (dorsal) vertebrae to the basi-occipital " and a dorsal portion confined to the spine. The superficial and more ventral portion enters into relation with the scalene to form the stem of the Y continuing on to the skull. It was identified Fig. i. Showing the position of the great thoracic rete with relation to the scalene muscle, thoracic cavity and cervical vertebrae. Rete dotted. a, Scalene muscle b, Rectus capitis amicus major muscle c, Longus colli muscle d, Trachelo-mastoid and splenius muscles e, Jugular vein /, Posterior thoracic and internal mammary veins g, Brachial vein h, Axillary venous plexus i, Right brachio-cephalic vein /, Left brachio-cephalic vein k, Precava /, Dorsal aorta m, Ductus arteriosus n, Carotid artery o, Subclavian artery p, Axillary artery q, Posterior thoracic artery r, Internal mammary artery s, Line of anterior extension of the pleural dome cv 1-7, Transverse processes of the cervical vertebrae 334 DISCOVERY REPORTS by Schulte with the rectus capitis anticus major muscle. The deeper and more dorsal portion was identified with the longus colli and is restricted to the bodies of the vertebrae. In both the foetuses dissected the scalene and rectus capitis anticus major were found to converge and unite somewhat anterior to the first rib (which is attached to the 7th cervical vertebra) at about the level of the 5th and 6th cervical vertebrae. Caudally the rectus capitis expands to a considerable belly opposite the first rib, and then diminishes to be inserted into the ventral surfaces of the first three or four dorsal vertebrae as far back as the point of contact of the dorsal aorta with the vertebral column. Fig. 1 shows the relations of these two muscles and the Y formed by them embracing the anterior extension of the thorax. It is seen that rostrally the two fused muscles, scalene and rectus, passing somewhat inwards and ventrally to their insertions into the skull, give place in the fore part of the neck to a complex of muscles composed of the splenial mesially and the trachelo-mastoid laterally (d). The former runs from the cervical neural spines to the squamosal bone and the latter from the dorsal parts of the first ribs to the squamosal. Fig. 1 also shows the heart turned aside to show the dorsal aorta (/), the ductus arteriosus (m) and the pulmonary artery. The lungs and most of the vessels on the left side of the neck have been omitted for the sake of clarity. The left subclavian, brachial and axillary arteries (p) are shown. The venous system is drawn somewhat displaced by the turning aside of the heart, but the " axillary venous plexus" is drawn in its normal position. The whole fork of the Y formed by the scalene (a) and the rectus capitis anticus (b) is occupied by the main mass of the rete mirabile (Fig. 1, dotted) which thus forms an irregular triangular mass. In Fig. 1 the pecked line (s), running through the dotted area representing the rete, marks out the extreme anterior limit of the pleural dome. Around its anterior aspect runs the posterior thoracic artery (q) and the posterior thoracic vein, which has been omitted for the sake of clearness. One side of the triangle formed by the rete between the rectus and the scalene muscles — the mesial side — rests dorsally against the vertebral column (cv) and ventrally against the rectus anticus muscle. Where the rete lies against the vertebral column it extends between the heads of the ribs and between the transverse processes, coming into contact at these points with the overlying dorsal musculature. It is found extending up into the neural canal through the intervertebral foramina, as was noted by Turner. The laterally directed side of the retial triangle lies against the scalene muscle, while behind it overlies the first intercostal space. The caudally directed side lies against the anterior extremity of the dome of the pleural cavity underneath the pleural lining (Fig- 1 )- The mesial relations of the rete to the vertebral column and the rectus capitis muscle and the lateral relations to the scalene are further shown in Fig. 2. This schematic diagram represents a transverse section through the posterior neck region. In section the scalene muscle (c) is shown to be somewhat arched for its insertion upon the ribs so that in front of the ribs its ventral face is nearly in contact with the rectus THE THORACIC RETE 335 capitis anticus major (e), leaving only a small slit, widening caudally, between itself and that muscle. In front, therefore, of the thorax the scalene forms a large part of the ventral boundary of the rete as well as the rectus. Through the slit the rete protrudes, so as to come into brief contact with the subcla- vian artery (g) and the sterno-mastoid muscle (di). The shape of the thoracic cavity is peculiar in the Cetacea. The diaphragm is very obliquely set and the ventral line of the cavity is far longer than the dorsal. The thorax projects far forward on each side in front of the heart and the great vessels, so that two domes of the thoracic cavity — the pleural domes — extend forward above the subclavian arteries nearly to the posterior face of the first rib. The forward extension of the dome is re- presented by the dotted line above mentioned on the right side of Fig. i. The caudal aspect of the pyramidal retial mass — the posterior side of the triangle — lies very close against this forward extension of the thorax underneath the pleural lining. It is therefore markedly concave in outline. It overlies the whole of the first intercostal area and the proximal third of the second, lying between the pleuron and the intercostal muscle. The main body of the retial mass occupies the length of the vertebral column from the i st cervical to the 4th dorsal vertebra and has the relations to the vertebrae already outlined. Between the 1 st and 2nd cervical vertebrae there is a large lobe of the retial substance which com- municates with the main body of the rete only by a neck passing through the foramen of the transverse process of the 2nd cervical vertebra. This portion is in relation laterally with the splenial and trachelo-mastoid muscle complex, and not with the scalene, which has passed me- sially to its insertion upon the basis cranii. Pos- teriorly, between the transverse process of the 4th and 5th and the 5th and 6th dorsal vertebrae , Fig. 2. Diagrammatic transverse section through the base of the neck, showing the main mass of the Rete (dotted) and its relation to the muscles and the vertebral column. a, Semispinalis muscle b, Longissimus dorsi muscle c, Scalene muscle d 1, Sterno-mastoid muscle d 2, Sterno-mandibularis muscle e, Rectus capitis anticus major muscle /, Longus colli muscle g, Subclavian artery h, Brachiocephalic vein i, Posterior thoracic artery j, Posterior thoracic vein k, Intraspinous vein /, Neural sinus m, Ascending artery n, Trachea and oesophagus 336 DISCOVERY REPORTS two further lobes of vascular network, apparently isolated from the main body, were found in the larger foetus (Fig. i). In the smaller they appeared to be joined to the main mass of the rete, forming a continuous band of the retial mass extending along the heads of the ribs as far as the 6th dorsal vertebra. In adult whales also these last two lobes appear to be isolated, so that the rete may be said to extend pretty continuously from the ist cervical to the 6th dorsal vertebra. RELATION TO BLOOD VESSELS The blood leaves the heart by the great aortic arch, which curves over the root of the left lung as described by Turner (Fig. 3). It gives off on its course the left common carotid and the left subclavian arteries from the summit of its curve. Shortly before the origin of the left common carotid, midway between the two lobes of the thymus gland (removed in Fig. 3), the brachiocephalic or innominate artery runs forward and outwards from the root of the systemic towards the right side of the body. Slightly lateral to the thymus it splits into the right common carotid and sub- clavian arteries, as in other mammals. On the left, as has been mentioned, these take origin from the systemic arch itself. On each side the subclavian continues forwards and outwards, running, in the proximal part of its course, ventral to the pleural dome, and distally over the ventral face of the scalene muscle. In contact with the inner face of the first rib the subclavian divides into a brachial artery, passing to the flipper, and an internal mammary artery, passing backwards across the middle of the ribs along the inner face of the side wall of the thorax. This artery supplies, by means of its numerous branches, the more distal portions of the intercostal spaces. The brachial artery is very small in comparison with the subclavian and internal mammary arteries. During its course beneath the pleural dome the subclavian artery gives off a stout branch — the posterior thoracic (Figs. 1,3,4 A), which runs round the anterior face of the pleural dome and backwards along the roof of the thoracic cavity underneath the pleuron; it is in contact with the ventral surfaces of the heads of the first five ribs, dis- appearing dorsally between the transverse processes of the 5th and 6th dorsal vertebrae. This artery forms a ridge at the extreme anterior face of the dome, causing a crescentic groove on the forepart of the lung where that organ presses against it. In its position and relations this posterior thoracic artery corresponds to a much enlarged superior intercostal artery, such as is found in other mammals. The posterior thoracic artery is accompanied mesially by a stout complementary posterior thoracic vein which emerges from between the 7th and 8th dorsal transverse processes (Figs. 1,3,46). This vein passes rostrally with regard to the corresponding artery on the inner faces of the ist and 2nd ribs, and is joined by the internal mammary vein. Blood returns from the flipper as a large brachial vein, which is joined by numerous plexiform veins from the ventral face of the scalene muscle between that muscle and the sterno-mastoid. This network forms an "axillary venous plexus" filling practically the whole of the space between these two muscles in the area of the axilla. It may, Fig. 3. The disposition of the main blood vessels in the neck region and the basis cranii. Thymus gland removed. a 1 , Internal pterygoid muscle a 2 , External pterygoid muscle a 3 , Palatoglossus muscle a 4 , Masseter muscle a 5 , Middle constrictor muscle of the pharynx a 6 , Depressor mandibulae muscle a 7 , Sterno-mandibularis muscle a 8 , Sterno-mastoid muscle a 9 , Scalene muscle b 1 , Dorsal aorta b 2 , Pulmonary artery b 3 , Ductus arteriosus b*, Left subclavian artery b 5 , Common carotid artery b 6 , Brachiocephalic artery b' ', Internal carotid artery 6 8 , External carotid artery b 9 , Posterior thoracic artery b 10 , Internal mammary artery b 11 , Brachial artery c 1 , Precava c 2 , Brachiocephalic vein c 3 , Brachial vein c*, External jugular vein c 5 , Internal jugular vein c 6 , Internal mammary vein c 7 , Posterior thoracic vein c 8 , Maxillary vein d 1 , Phrenic nerve d 2 , Pneumogastric nerve d 3 , Fifth nerve d*, Hypoglossal nerve e, Mandible /, Nasopharynx g, Larynx h, Meckel's cartilage i, Tympanic bulla j, Lung k, Heart 338 DISCOVERY REPORTS indeed, be mentioned here that there is a general tendency, noted by most previous authors, towards a plexiform arrangement of all the venous channels of the body: the interstices of all the tissues all over the body of a Rorqual foetus are filled with these anastomosing venous channels. The brachial vein enters the brachiocephalic trunk by a short wide stem formed by the brachial, axillary plexus and internal mammary, and this may perhaps be considered to represent the subclavian vein. The two brachiocephalics join to form a wide precava entering the right auricle (Fig. 3). The posterior thoracic artery and vein constitute the main trunks supplying and draining the great thoracic rete and the anterior intercostal areas. Between the 5th and 6th rib (Fig. 4 A) the posterior thoracic artery turns dorsally, and running upwards and outwards, supplies by numerous twigs the longissimus dorsi and semispinalis muscles above the 5th dorsal vertebra. Between each pair of ribs anterior to this and in front of the 1st rib, which is cervical in its attachment, the posterior thoracic artery has a branch to the dorsal musculature similar to that between the 5th and 6th rib (Fig. 4 A). These are of increasing calibre as the series passes forwards and the first of them, which is directed more obliquely than those behind it, is a fairly stout trunk serving the muscles above the neck by numerous tufts of branches. The dorsal musculature behind the 6th rib is supplied by a series of very much smaller trunks arising from the segmental intercostal arteries of the dorsal aorta (Fig. 4 A). It is thus seen that the blood supply to the dorsal muscles becomes increasingly generous towards the anterior end of the body. The posterior thoracic vein emerges from the neural canal behind the 7th dorsal vertebra. It passes downwards between the 7th and 8th ribs (Fig. 4 B), where it turns forwards, and after passing ventral to the head of the 6th rib, accompanies the posterior thoracic artery forwards to the anterior end of the thorax, where it has the relations already described. A large thin-walled venous sinus accompanies the spinal cord latero-ventrally on either side within the neural canal of the vertebral column. Between the vertebrae, within the neural canal, the two venous sinuses on either side receive cross connections, so that there is a ladder-like system of large venous channels lying in the neural canal ventral to the spinal cord. These sinuses extend as far forward as the 7th cervical vertebra, where, on each side, they turn ventrally to form the first thoracic intraspinous vein of the series, shortly to be described, draining into the posterior thoracic vein. Anterior to that point, up to the foramen magnum, the neural canal is filled with a plexus, which is entirely venous, embracing the spinal chord and entering the skull through the foramen magnum to form a vascular mass against the hinder surface of the brain. Throughout the whole of their course in the neural canal these two large sinuses receive veins between the vertebrae entering the canal by the foramina between the neural spines (Fig. 4 B). Between the 7th and 8th dorsal vertebrae the vein traversing the foramen between the neural spines is the first of the series draining from the neural venous sinus into the posterior thoracic vein. It turns forward, as has been already stated, ventral to the 6th rib to form the posterior thoracic vein itself. Similar intra- cu > CO d SB N C CJ cu £ cu *-> X> 60 CO cu JO g £ *-* cu c/3 ej Jd CO d CJ 4-» o J- >-> •J cu *fl 3 CU 1- O 3J CO 1-t jd H u 4-> JJJ a *-> CO X. O o CU CJ O CJ .d CJ CU 'cj t-l -4-» 3 'o 1- cd cu CU fl cd IH cu *J o cl JS o _d o g '-*-. J3 *-■ -a ja o -3 a cu u "3 d CU o ■4-J "c3 CO O "3 4-J d CU u o 1 cu H 6S CO S 5b cj o CD CO -a pel cu CO 1 .9 CO DQ u *CU Ui CJ -1-t tS > O 3 CJ M cu -a C< 4) Jd j3 O s 4-< l+H b Ch o do cu o lis CJ c Jd o ix d 73 CO cu 'cO g 0) CO S CO g ,d 'S > 'co o O d o £ B c O cu O a, 'J3 cu J3 "cu o ca H3 -a d M d o 60 C ^3 a CJ o CO < CO T3 e a C XI CO 'S > CO 3 O g V M g ca 3 O d 'En CO 3 d i — i 60 d ■a d CJ O CO cu Q 'C CJ s CO 5 00 ca CJ c •S3" 13 i-< '5. CO cu" ^ «S ft cu cfl 1- cu J3 4-4 H d cu < PQ J2 4-» T3 ■<*• 6o d cd >> CU E CO d '5 > 60 d ^3 d cu CJ CO C "cu > g > "3 M tn O CS C cu -a cu .d H u o "3 x: Oh o 'v > O *-> O 1? CO 1-4 o Q o e "3 Pi ~a o Q 2 o M 1- P3 CD 3 60 3 '£ CJ 4-* CO O P-. e~ rfi" cj" "« 34 o DISCOVERY REPORTS spinous veins from the neural venous sinuses pass to the posterior thoracic between all the dorsal vertebrae up to the 7th cervical. Anterior to that, up to the 1st cervical, the intraspinous veins, of which there are six in the neck region, appear to take origin from the network of venous capillaries that fills the cervical portion of the neural canal. From the 8th dorsal vertebra to the 7th cervical vertebra there are thus eight veins connecting the neural venous sinuses and the posterior thoracic vein. They become increasingly stout forwards and the first four or five of the series are very wide indeed and have thin walls. Those between the 7th cervical and 1st dorsal and the 1st dorsal and 2nd dorsal join and enter the posterior thoracic by a common trunk between the 1st and 2nd rib. The intraspinous veins in the neck have the arrangement shown in Fig. 4 B. The vein emerging from between the 1st and 2nd cervical vertebrae passes through the large foramen in the transverse process of the 2nd cervical vertebra and is then joined by its successor to form a single vein running under the basal processes of the vertebrae in front of the 7th cervical. A stem from the 3rd and 4th, 4th and 5th and 5th and 6th meets it, and after receiving another from the 6th and 7th, it enters the posterior thoracic vein ventral to the head of the first rib in common with the first two thoracic intraspinous vessels (Fig. 4 B). Behind the 8th dorsal vertebra the thoracic intraspinous veins drain into a small independent trunk on each side of the vertebral column. These will be described when the intercostal blood supply is dealt with. In the abdomen the intraspinous veins connect the neural venous sinuses with the postcava and still further caudally with the caudal veins. These posterior connections will be referred to again, but it is desired to mention them here in order to point out that the neural venous sinuses must serve the purpose of reservoirs. They do not form part of the blood drainage back to the heart from any set of organs or from any region of the body. Anteriorly they are cut off from direct communication with the brain by vascular plexiform masses filling the neural canal. They are in direct and wide communication with the great veins of the body, and the blood would appear to flow in either direction in the connecting intraspinous vessels — that is upward in the abdominal region and downward in the thoracic region, or vice versa, without impeding the flow towards the heart. Thus in the Fin Whale they provide direct connection between the precaval and postcaval venous systems alternative to that provided by the heart. Veins exactly complementary to the arteries ascending to the dorsal musculature join the intraspinous veins of the posterior thoracic system shortly after these leave the neural canal. Their course follows that of the arteries and they, likewise, increase in calibre forwards. Behind the 6th rib they drain into the segmental veins shortly to be described (Fig. 4 B). The vascular masses of the rete mirabile are found surrounding the posterior thoracic artery as far back as the 4th dorsal vertebra and the roots of all the six arteries which ascend to the dorsal musculature from it. The masses of the rete lie between the trans- verse processes of the vertebrae and the heads of the ribs concerned. In the same way the rete surrounds the posterior thoracic vein and all the thoracic intraspinous veins except the last two. It also surrounds the intraspinous veins in the cervical region. It extends THE THORACIC RETE 341 along them between the transverse processes and up into the neural canal, where it surrounds their junctions with the venous sinuses running in the canal. The intraspinous veins are thus embedded in the retial substance throughout their course from the neural canal to the posterior thoracic vein, but the ascending arteries pass out between the heads of the ribs considerably more laterally, and thus are only surrounded by retial substance at their roots, where they pass between the ribs. These veins and arteries are in communication with the rete wherever they pass through it by means of innumerable small arterioles and venules and by somewhat stouter twigs. From many points on the main posterior thoracic trunks, also, small arteries and veins run to various parts of the rete, particularly around the proximal parts of the posterior thoracic vessels. The ascending arteries passing through the rete diminish somewhat in calibre after leaving it — that is dorsal to it. The intraspinous veins are correspondingly somewhat increased — that is ventral to the rete. The retial masses are confluent above and below the heads of the ribs, forming a continuous enveloping mass as far as the 6th rib. However, in the 1-73 metre foetus the masses of retial substance surrounding the last two ascending arteries and the corresponding intraspinous veins were isolated from the main mass of the rete, and formed two lobes quite separate from the rest of the organ between the heads of the 4th and 5th and the 5th and 6th ribs. In the smaller foetus these two lobes seemed to be joined to the main body. In the abdominal region each of the segmental ascending arteries, corresponding to those described above for the thoracic region, leaves the dorsal aorta as a single mid- dorsal trunk, which soon bifurcates, its branches passing to the dorsal musculature on either side of the vertebral column. The descending intraspinous veins from the neural venous sinuses drain into the postcava, as has already been mentioned. The postcava in the abdominal region consists of a pair of trunks, the venae iliacae (Daudt, p. 280), which run forward parallel with one another as far as the anterior end of the kidneys. Here they fuse to form a single median postcava, which has thus only a short course within the abdominal cavity before it penetrates the diaphragm. The venae iliacae on either side receive their intraspinous veins from the corresponding neural venous sinus of that side of the body. Farther caudally the ascending arteries are given off by the caudal artery and the intraspinous veins received by the caudal veins. Thus the neural venous sinuses are connected to the postcaval system throughout the whole length of the body and the precaval and postcaval venous systems are in open communication with one another by way of the neural canal. The descending veins between the 6th and 12th lumbar vertebrae break up into a complicated venous network on the ventral aspect of the vertebral column as shown in Fig. 5. Presumably this network serves to facilitate the flow of blood from the post- cava to the neural venous sinuses in the lumbar region of the body and in the opposite direction also. The posterior thoracic system is not only responsible for the blood supply to the rete mirabile and the dorsal musculature, but it also serves the anterior intercostal Fig. 5. The lumbar venous plexus. a, Rectus abdominis muscle h, Intraspinous vein b, Rectum j, Segmental ascending artery c, Uterus j, Hypaxial muscle d, Dorsal aorta k, Caudal vein e, Right postcava /, Caudal artery /, Bladder m, Fifteenth lumbar vertebra g, Ureter «, First caudal vertebra THE THORACIC RETE 343 spaces, as do the superior intercostal arteries and veins of other mammals. It will be con- venient to give a brief description of the blood supply to the intercostal areas generally. The middle and distal parts of the intercostal musculature are served by numerous branches of the internal mammary system. Mention has already been made of these and they need not be further described. All the intercostal areas behind and including the 6th (that is, behind the 6th rib) are supplied from the dorsal aorta by means of segmental arteries (Figs. 4 A and 6). Each of these passes outwards, ventral to the intervertebral ligaments, and splits into an ascending branch to the dorsal musculature, serial with those coming off from the posterior thoracic, and a main intercostal branch to the intercostal muscles (Figs. 4 A and 6g, d). In front of the 6th intercostal space the supply is derived not from the dorsal aorta but from the posterior thoracic artery (Fig. 6 b), which gives off a double series on each side. Each of the 3rd, 4th and 5th intercostal spaces is served by a branch from the posterior thoracic artery, serial with those from the aorta, and by a smaller branch serving their proximal parts. The 1st and 2nd intercostal spaces are not supplied with blood by means of arteries, either from the dorsal aorta or from the posterior thoracic, but are covered by the main body of the rete mirabile, which appears to be in intimate contact with the musculature underneath the pleuron. The 1st space is completely covered by the rete, and receives no branches from the internal mammary system, while the 2nd space is covered for about its proximal third and receives distally the first of the internal mammary series. The intercostal venous return may broadly be said to be complementary to the arterial supply. The 8th space and all those behind it are drained by pairs of segmental veins. The 3rd, 4th and 5th drain into the posterior thoracic vein, while the 6th and 7th must be regarded as transitional since they contribute to both systems (Figs. 4 B and 6). Behind the 7th space — that is in the 8th and all behind it — the intercostal veins and the descending intraspinous veins on each side drain into a small vein which runs ventral to the bodies of the vertebrae and arches over the segmental arteries at their origins from the aorta. These small veins run mesial to the ganglionated chords on each side. Just in front of the 6th dorsal vertebra the right member of this pair of venous trunks crosses the posterior insertion of the rectus capitis anticus muscle and joins the left- hand member of the pair at the level of the 3rd dorsal vertebra. The resulting single trunk enters the brachiocephalic vein above the root of the left lung (Fig. 6). It has been stated by all authors that the azygos and hemiazygos veins of other mammals are absent or very much reduced in the Cetacea. Breschet and Bouvier were both of the opinion that the neural venous sinuses take the place of the azygos system. In the account given by the former author (pp. 18-19, P^ 4> %• J ) trie l ar g e descending intraspinous vein between the 3rd and 4th rib was described and figured on the left side only, while that on the right was omitted, so that the neural venous sinuses were stated by Breschet to present an azygous condition. Bouvier noted that the neural venous sinuses were not azygous, but nevertheless considered them analogous in function to the azygos vein. Owen (vol. in, p. 553) stated that in the Porpoise the Fig. 6. Arrangement of the intercostal arteries and veins. a, Internal mammary artery and veins e, Left posterior thoracic artery b, Left brachiocephalic vein /, Left posterior thoracic vein c, Left subclavian artery g, Left azygos vein d, Rete mirabile h, Dorsal aorta THE THORACIC RETE 34S definition of any distinct azygos or hemiazygos trunk is obscured by the characteristic expansion and plexiform multiplication of the veins at the back of the thoracic cavity. Schulte (p. 467) quotes von Baer as stating that the azygos is missing altogether in the Porpoise, while in the Sei Whale Schulte (pp. 467-8) describes it as present rudi- mentarily. He mentioned a small venous trunk having a zig-zag course above the ganglionated chord on the right side, receiving laterally branches from the right inter- costal spaces and mesially branches from the left intercostals. Possibly the small vessel described by Schulte corresponds to the right-hand member of the pair found by me. It is suggested that this pair of small veins and the single trunk by which it joins the left brachiocephalic are the homologues of the azygos veins. There is considerable variation in the disposition of the azygos throughout the Mammalia (Owen, vol. in, P- 555)- Among the Marsupials both azygos veins are present in the primitive Saurian post-cardinal position. In the Ungulates there is a single (right) azygos entering the single (right) precava. In the Hog the single left azygos enters the right auricle directly. In the Antelope two azygos veins are present — the left being the larger (Owen, quoting Hunter, vol. ill, p. 555). In the Rhinoceros the right precava receives the right azygos vein while the left drains into the left subclavian. That the azygos of the Fin Whale, then, should lie on the left and enter the left brachiocephalic (innominate of other mammals) is not an unusual feature. It may be said, therefore, that the descending intraspinous veins (Figs. 4 B and 6) and the intercostal veins of the 6th space and all those behind it enter the azygos venous system. They are complementary to the corresponding ascending and intercostal arteries which are derived from the dorsal aorta. In the 7th intercostal space, however, the main intercostal vein joins the posterior thoracic as well as the azygos, to which small cross connections also run (Figs. 4 B and 6). This is also observed in the 6th space, so that these two spaces would appear to be transitional between the segmental and posterior thoracic intercostal systems. In the 5th space veins exactly complementary to the arteries drain into the posterior thoracic. In the 4th and 3rd spaces the intercostal veins also empty into the posterior thoracic system, but may show slight variations. For example, in the larger foetus the veins from these two spaces on the left side joined together to form a common trunk before reaching the posterior thoracic. In the smaller foetus they passed straight into that vein on both sides of the body. The 1st and 2nd spaces are, as already stated, covered by the rete. From the above description and from the figures it will be seen that the intercostal blood supply is derived from four sources : (i) The internal mammary, supplying the middle and distal parts of all the spaces except the first. (ii) The segmental system, supplying the 6th space and all behind it. (iii) The posterior thoracic system, supplying the 3rd~5th space, (iv) The rete mirabile, which overlies the whole of the 1st and the proximal part of the 2nd space. 3-2 346 DISCOVERY REPORTS It may be observed also that there is an increasingly generous blood supply to the intercostal muscles proceeding forwards. The branches from the posterior thoracic are bi-seriate (Fig. 6), and tend to be of larger calibre rostrally than posteriorly. The posterior thoracic arteries and veins corre- spond to a much enlarged and accentuated superior intercostal system, such as is found in other mammals. By their contact with the rete mirabile the first two intercostal spaces are probably the most generously supplied with blood of the whole series. RELATION TO NERVES The pneumo-gastric nerve (Fig. 3 d 2 and Fig. 7/) accompanies the carotid artery and the jugular vein, passing above the short subclavian vein and under the subclavian artery to its destination in the roots of the lungs and heart. The phrenic (Fig. 3 d> and Fig. 7/) is de- rived from the 4th cervical spinal nerve, and accompanies the pneumo-gastric as far as the great vessels, where it diverges and crosses the body of the lung to the diaphragm. The 5th, 6th, 7th and 8th cervical spinal and the 1st thoracic spinal nerves (Fig. 7 cr 5 - 8 , tr 1 ) contribute to the cervico-brachial plexus, passing through a slit in the scalene muscle to reach it. The cervical sympathetic chord (Fig. yg) accompanies the pneumo-gastric as far as the 7th cervical vertebra, where it passes outwards and somewhat upwards into the Fig. 7. Nervous relations of the thoracic rete. The rete is dotted. Part of the posterior thoracic vein has been omitted in order to show the nerves underneath. /, Pneumo-gastric nerve k, Retial ganglion g, Cervical sympathetic chord /, Phrenic nerve //, Thoracic sympathetic chord /', Middle cervical sympathetic ganglion j, Posterior cervical sympathetic ganglion a, Dorsal aorta b, Carotid artery c, Jugular vein d, Posterior thoracic vein e, Pulmonary artery cr 3 ~ B , Cervical spinal nerves tr 1 ' 5 , Thoracic spinal nerves THE THORACIC RETE 347 body of the rete. In the middle of the retial mass it forms the middle sympathetic gang- lion (Fig. 7 i) — a large stellate ganglion lying opposite the ist rib. Small sympathetic nerves run from it into the body of the rete. The middle cervical sympathetic ganglion receives rami from the 5th, 6th, 7th and 8th cervical and the ist thoracic spinal roots — all those which form the cervico-brachial plexus. From the hinder part of the ganglion there is given off a bundle of nerves forming a plexus whose components run above and below the posterior thoracic vein (Fig. 7). On emerging from the body of the rete they join up to form a pair of nerves passing to the heart and lungs. One of these has a ganglion on its course — the retial ganglion (Fig. 7) — and receives a long ramus from the 4th cervical spinal, from which the phrenic is also derived. The retial ganglion lies a little behind and dorsal to the posterior thoracic vein and also gives off nerves into the substance of the rete. Nerves also run into the rete directly from the cervical and thoracic spinal roots — the most conspicuous being a stout retial nerve from the ist thoracic, which ramifies among the retial capillaries in the neighbourhood of the posterior thoracic vein. The posterior cervical sympathetic ganglion lies more dorsally within the retial substance, close up against the heads of the 3rd and 4th ribs (Fig. yj). It is connected with the middle ganglion by two stout chords : these have cross connections and really form a short plexus. The posterior ganglion receives rami from the 2nd and 3rd thoracic spinal nerves, and gives off yet a third sympathetic nerve to the heart and lungs, running across the distal part of the aortic arch to reach its destination. The main thoracic ganglionated chord leaves the posterior cervical ganglion and runs as usual across the heads of the ribs forming segmental ganglia, each of which has the usual rami running to the spinal roots. The ist of these segmental ganglia lies between the heads of the 4th and 5th ribs (Fig. 7). In the larger foetus there appeared to be communication within the rete between all the spinal nerves contributing to the two sympathetic ganglia, and fibres could be seen running from these spinal branches to the three sympathetic nerves to the heart and lungs. The two sympathetic ganglia were very closely invested by the retial substance, which formed a compact mass around them. From the above it appears that the rete is mainly under the control of the sym- pathetic system, while to some extent it is evidently under the control of the somatic as well. SUMMARY The thoracic rete is a network of vascular capillaries situated around the anterior extremity of the thoracic cavity, in the fork formed by the convergence of the rectus capitis anticus major and the scalene muscles passing to their joint insertion upon the basis cranii. The rete is independent of surrounding structures, but in close contact with the muscles of the first two intercostal spaces. The vascular networks extend along the vertebral column and between the heads of 348 DISCOVERY REPORTS the ribs from the ist cervical to the 6th dorsal vertebra. They pass up between the transverse processes into the neural canal. Two large thin-walled venous sinuses accompany the spinal chord as far forward as the 7th cervical vertebra. Anterior to this the canal is filled with a venous plexus extending into the skull through the foramen magnum and embracing the back of the brain. From the neural venous sinuses intervertebral (descending intraspinous) veins descend throughout the whole length of the body. In the neck region they are found also collecting themselves from the venous plexuses in the neural canal. As far back as the 8th dorsal vertebra the intraspinous veins join the posterior thoracic. Posterior to the 8th dorsal vertebra they join the small azygos veins which have been shown to exist. In the abdominal region they drain into the postcava. The precaval and postcaval venous systems are thus in free communication with one another through the neural canal, and blood reaches the heart from the neural venous sinuses in whichever direction it flows in them. Appearances suggest that these sinuses are blood reservoirs. The rete surrounds all the descending intraspinous veins back to the 6th dorsal vertebra. It surrounds them throughout the whole of their course and is in free com- munication with them by means of numerous subsidiary twigs. The rete surrounds the posterior thoracic vein and artery in the proximal parts of their course and also the roots of the arteries ascending to the dorsal musculature from the posterior thoracic. The rete is everywhere in free communication with the vessels it surrounds, whether arteries or veins. It does not, however, block the course of any of them. This is opposed to the earlier conceptions of the retia, according to which these networks were supposed to be formed on the course of either an artery or a vein. The foregoing description shows that they must be looked upon as capillary systems intervening between arteries and veins. The rete is in intimate contact with the muscles of the ist and 2nd intercostal spaces. The blood supply to the intercostal muscles becomes increasingly generous proceeding forwards. The rete is mainly under the control of the sympathetic nervous system but to some extent of the somatic as well. THE BASICRANIAL RETE The cavity between the tympanic bulla and the articulation of the mandible is occupied by a vascular network similar in appearance to the thoracic rete already described, i.e. consisting of intimately related arteries and veins. RELATION TO SKULL The shape of the skull and the form of the basis cranii are extremely different in foetus and adult. The position and relations of the basicranial rete were only examined in detail in the foetus. From a general inspection of the adult basis cranii, however, it THE BASICRANIAL RETE 349 seems that the rete holds the same relations to the surrounding parts in the adult as in the foetus, but in consequence of the change in size and shape of those parts the form and relative size of the rete has undergone considerable alteration. A B Fig. 8. A. Skull of a foetal Sei Whale, ventral view (from Schulte). B. Skull of an adult Sei Whale, ventral view. Showing the difference in the arrangement of the parts of the basis cranii in the foetus and adult a < MaxiUa h, Pterygoid bone b < Vomer l, Squamosal f ' Palat,ne j, Tympanic d > Frontal k, Exoccipital e, Internal pterygoid plate /, Basi-occipital /, External pterygoid plate m> Basi-sphenoid g, Hamular process The chief differences between the foetal and adult cranium (Fig. 8) are to be seen in the short broad rostrum and the flat palate of the foetus, which contrast very markedly with the prominent raised palatal ridge and the elongated pointed rostrum of the adult Ihe rostrum is formed in the adult by the enormously lengthened maxillae embracing 35o DISCOVERY REPORTS the vomer between them. The foetal brain case is of great size and domed, while the lateral projections of the frontals and squamosals are very small in comparison with those of the adult, where the squamosals form two large postero-lateral downwardly curved wings. The base line of the foetal skull is horizontal and the whole plane of the basis cranii broad and flat, while in the adult it curves strongly downwards from the great wing-like projections of the maxillae. The foetal maxillae are of comparatively small size, while the palatines and pterygoids are large, the latter projecting backwards on either side of the posterior nares to form two rounded bosses — the hamular processes (Fig. 8). Schulte (1916, pp. 476-7; pi. 54, fig. 2; pi. 55, fig. 2) distinguished two parts of the ptery- goid bone of the foetal Sei Whale, an internal and an external pterygoid respectively, separated by a suture. Ridewood (1922, pp. 263-4), however, did not confirm the presence of this suture in the skull of the Sei Whale foetus examined by him, nor in the skulls of foetal Megaptera nodosa. This author believed that the pterygoid bones figured by Schulte are in reality parts of the palatine. While the predominating features of the adult basis cranii are the laterally projecting squamosals and the large wing-like maxillae, the predominating feature in the foetus is the enormous tympanic bulla with its tube-like meatus. It is joined to the mandible by a slender strip of cartilage — Meckel's cartilage — enclosed in a fibrous sheath. In the adult the bulla is a relatively very small fist-shaped bone concealed on the inner side of the squamosal wing. It forms a quite insignificant feature of the occipital region. In the foetus the basicranial rete lies on the ventral surface of the squamosal bone, in a cavity between the enormous round dome of the tympanic bulla and the articulation of the mandible. It extends over the external pterygoid plate and the alae temporales into the orbit. It thus occupies a large crescent-shaped space in the foetus. In the adult, however, the dimensions of this space are much reduced owing to the shrinkage of the bulla and the pterygoid and the development of the fibrous articulation of the mandible which occupies most of the squamosal wing. So far as could be made out the greatest extension of the adult rete is vertical, so that it forms a fatty vascular mass, similar in appearance to the thoracic rete, extending upwards into the fissure between the squamosal and the basioccipital bones, where lies the small fist-like tympanic. It appears also to extend on to the pterygoid in the adult, but this part is concealed by the broad internal pterygoid muscle. RELATION TO MUSCLES The cavity occupied by the rete in the foetus thus extends from the orbit to the extreme posterior limit of the tympanic bulla (Fig. 9). It underlies the tympanic ventrally, and is laterally bounded by the masseter muscle and the attachment of the pterygoid muscles to the mandible. The broad sheet-like internal pterygoid muscle forms the floor of the space, and the mesial boundary of it is made up of the palato- glossus muscle and the middle constrictor of the naso-pharynx. The palato-glossus has THE BASICRANIAL RETE 351 a broad fibro-muscular attachment to the palate and to the hamular processes at the root of the tongue. It thus separates the rete and the cavity it occupies from the posterior nares. Immediately posterior to the nares is a large cavity with fibro-muscular walls — the naso-pharynx — in the formation of which the palato-glossus muscle takes a large part. The naso-pharynx contains the larynx and associated structures. Two great constrictor muscles, of which the largest is the middle constrictor, run from the wall of the naso-pharynx to the stylo-hyoid cartilage. Both this cartilage and the middle constrictor muscle are shown cut through in Fig. 9. In the posterior half of the rete the middle constrictor muscle forms its mesial boundary. Anteriorly the mesial boundary is formed by the palato-glossus as already mentioned. The middle constrictor also forms a large part of the posterior boundary of the rete. There is thus a space, bounded by the squamosal bone and the tympanic bulla dorsally, by the mandible and the masseter and pterygoid muscles laterally, by the belly of the inter- nal pterygoid muscle ventrally and by the palato-glossus and middle constrictor mesially and posteriorly. Here the rete is found, forming a large crescent-shaped highly vascular mass, exactly similar in appearance to the thoracic rete already described. It resembles the latter in that it is invested in its own fibrous integument, and is easily dissected away from neighbouring cartilages and muscles, with which it appears to have no intimate relation. The thoracic rete, however, is very much more diffuse. The basicranial rete completely surrounds and envelops the external pterygoid muscle, which runs through the midst of it from the external pterygoid plate of Schulte (Fig. 9) to its attachment to the mandible. It also surrounds Meckel's cartilage, which forms a narrow cartilaginous rod within a fibrous sheath running from the bulla to the mandible across the space occupied by the rete. RELATION TO BLOOD VESSELS Like the thoracic rete the basicranial rete is composed of intimately related arteries and veins. The external carotid artery, cervico -facial of Turner, which passes from the com- mon carotid along the lateral part of the face towards the orbit and maxilla, traverses the centre of the basicranial rete dorsal to Meckel's cartilage (Figs. 3 and 9). During its course through the rete it repeatedly gives off short many-branched arteries to the retial substance. A branch runs to the lower jaw from the cervico-facial shortly before that artery reaches the rete. Opposite the orbit the cervico-facial splits into an orbital and a maxillary branch. A vein, the pterygo-maxillary, runs from the palatine border of the maxilla diagonally across the attachment of the internal pterygoid muscle to the palate. It passes external to the hamular process, and runs closely adherent to the fibro-muscular wall of the pharynx, around the inner and posterior surface of the tympanic bulla, to join the jugular vein. Its course over the attachment of the internal pterygoid muscle is plexiform, and it receives a network of veins at this point from the mesial and ventral parts of the rete. The main body of the rete is drained by a pair of veins having a rostral direction and joining up with the orbital vein to enter the pterygo-maxillary behind the orbit. From the mandible a plexus of small veins breaks up among the capillaries of the rete. a, Maxillary vein b, Maxillary artery c, Retial veins d, Orbital vein e, Orbital artery Fig. 9. Position and relations of the basicranial rete. i, Masseter muscle p, Stylo-hyoid cartilage j, Plexiform arteries and veins g, Middle constrictor muscle of the pharynx from the mandible k, Fifth nerve /, Retial nerve /, External pterygoid muscle m, Meckel's cartilage g, Internal pterygoid muscle «, Tympanic bulla h, External carotid artery 0, Retial arteries ;•, Hypoglossal nerve s, Depressor mandibulae muscle /, Sterno-mandibularis muscle 11, External jugular vein v, Internal jugular vein w, Palato-glossus muscle THE INGUINAL PLEXUS 353 It may be mentioned that a slender vascular plexus lies between the distal parts of the common carotid artery and the internal jugular vein, close to the origin of the pterygo-maxillary and internal carotid arteries. This rete drains into the internal jugular vein. There is indeed a high degree of vascularity in all the tissues around the base of the skull and the cranial part of the neck region. The general tendency of the venous channels in the Fin Whale to a plexiform disposition has already been noticed, and has been observed in Cetacea by other authors (Owen, for the Porpoise). RELATION TO NERVES Among the vascular networks of the basicranial rete there is a complex of fine nerves taking origin from the trigeminal. A special retial branch leaves the fifth nerve at its point of emergence from the cranium immediately in front of the tympanic bulla and passes in a caudal direction (Fig. 9), ventral to Meckel's cartilage, distributing nerves to the surrounding vascular capillaries. Further branches to the rete leave the fifth nerve before its emergence from the skull and accompany it through the fenestra. SUMMARY The basicranial rete lies at the base of the skull in a cavity between the articulation of the mandible and the tympanic bulla. It is bounded by the internal pterygoid, palato-glossus and middle constrictor muscles. It receives numerous fairly stout branches from the external carotid artery, cervico- facial of Turner, and drains into the pterygo-maxillary vein. It is innervated from the trigeminal nerve. One of the chief features of the basicranial rete is its separateness from surrounding structures. It is invested by a connective tissue integument, and can be dissected away from surrounding muscles. Like the thoracic rete, however, it possesses its own arteries, veins and nerves, and does not lie upon the direct course of any main blood vessel. It is, indeed, even more discrete and compact than the thoracic rete, and the vessels that supply it are distinct and separate vessels to an extent even more marked than in the thoracic rete. Judging from the disposition of the arterial supply and venous drainage, it may be suggested that the blood which enters the rete is entirely arterial and the rete, unlike the thoracic one, is an entirely arterial structure. The thoracic rete, as already indicated, is partly arterial, but from its arrangement would appear to be to a larger extent venous. Blood must be supposed to enter the basicranial rete from the cervico-facial artery and to leave it by subsidiary veins draining into the pterygo-maxillary vein. THE INGUINAL PLEXUS A large vascular network is situated in the inguinal region and appears to be intimately related to the inguinal lymphatic glands. It is not proposed to employ the term " Rete Mirabile" for this plexus, since its appearances suggest a difference in nature from 4-2 354 DISCOVERY REPORTS the basicranial and thoracic retia described above. The plexus takes the form of a diffuse vascular mass situated on either side of the bulbus penis in the male (Fig. 10) or of the vagina in the female. It lies between the bulbus or vagina and the posterior Fig. io. The genital region of a foetus 177 metres in length showing the three arcades formed by the attachments of the rectus abdominis muscle and the vessels concerned in the formation of the inguinal plexus. a, Epigastric artery b, Iliac artery c, Inguinal lymphatic glands d, Caudal attachment of the rectus abdominis muscle e, Iliac attachment of the rectus abdominis muscle /, Superficial attachment of the rectus abdominis muscle g, Pelvic rudiment h, Ischio-cavernosus muscle (, Retractor penis muscle j, Ischio-caudalis muscle k, Levator ani muscle insertions of the rectus abdominis muscle. It is intimately related to the two very large lymph glands which are situated in this position and are presumably the homo- logues of the inguinal lymph glands of other mammals.- On each side of the body one of these lymph glands (Fig. 10) lies against the prostatic portion of the urino-genital THE INGUINAL PLEXUS 355 duct or the lower part of the vaginal canal. The other overlies the epigastric artery and vein where they pass together from the iliacs on to the parietes of the abdominal cavity. The glands are surrounded by dense concentrations of vascular substance (especially the one lying against the prostate or vagina), which peripherally spread out in a diffuse manner among the surrounding blood vessels and muscles. A similar diffuse network extends up the middle line of the body in close relation to the lymph tract occupying that area. Although the disposition of the lymph tracts all over the body was not studied and does not form the subject of the present paper, it may be mentioned that vascular plexuses, similar to this one in the inguinal region, are found wherever there is a concentration of lymphatics. These plexuses are diffuse and ill-defined, and evidently different in nature, and thus probably in function, from the two great retia in the thorax and basis cranii. The plexus in the inguinal region, however, is so large and dense, and occupies such an extensive area, that some description of its relations is justified. The rectus abdominis muscle has a threefold posterior attachment. An inner portion, described by Carte and Macalister (pp. 223-4), narrows to a tendinous attach- ment to the anterior chevron bones. A central slip is attached to the ilium of the rudimentary pelvis. A third and outermost slip has a triangular insertion upon the lumbar fascia between the ischio-caudalis and hypaxial muscles, immediately lateral to the bulbus penis or to the vulva. There are thus two muscular arcades on each side of the genital region admitting nerves and blood vessels. The outer arcade is formed by the insertion of the rectus abdominis into the lumbar fascia on one side and the ilium on the other. This arcade admits a stout vein from the superficial fascia of the pedicle. This has plexiform anastomoses with the iliac veins. A stout lumbar nerve accompanies this vein, but there is no complementary artery. The inner arcade is formed by the iliac insertion of the rectus abdominis and the part passing to the chevron bones. It admits the pudic arteries and veins with their accompanying nerves. These vessels, together with the lumbar veins just mentioned and the epigastric arteries and veins, contribute to the formation of the plexus around the two lymph glands. The plexus is continued rostrally towards the two kidneys on either side of the middle line of the body beneath the peritoneum, where it is in close association with the lymph glands which occupy that tract. It receives small arteries from the aorta in this region and is drained by small veins to the two large iliac branches of the postcava. In the region of the inguinal plexus there are numerous sympathetic nerves, connected with the hypogastric nerve plexus, and the stout somatic nerves to the genital region run through the inner arcade of the rectus muscle on to the penis and clitoris. It did not appear, however, that the vascular plexus was innervated by any of these, although they run through the midst of it. The plexus can be dissected away from around them along their whole course, and no small nervous twigs were found running to the plexus, such as were seen in the thoracic and basicranial retia. 356 DISCOVERY REPORTS SUMMARY It seems that the plexus in the inguinal region is different in nature and function from the others described in this paper. It is in intimate relation with the lymph glands and their channels and has no innervation that could be detected in dissection. It is far more diffuse in texture than the thoracic and basicranial Retia and has not the connective tissue investment that was found in the latter. Murie (1873, PP- 290-1) has noted the close association of lymphatics and vascular networks, and it may be that, as he has suggested, these networks afford interchange between the blood and the lymphatic systems. DISCUSSION The following facts have emerged from the foregoing description of the retia mirabilia and their relations. 1. The retia are vascular masses closely investing certain arteries and veins, but not forming an integral part of them. They do not impede the flow of blood in any direction either away from or towards the heart. They are supplied with blood by their own arteries and drained by their own veins. Thus they are independent organs, and not merely constrictor mechanisms on the course of the main blood-system. It is therefore incorrect to describe them as either arterial or venous. The blood, however, which enters the thoracic rete must be mainly venous, entering it from the neural venous sinuses. A smaller proportion will be arterial, entering the rete from the posterior thoracic artery. The blood which enters the basicranial rete must be supposed to be mainly arterial, derived from the main facial artery. 2. The precaval and postcaval venous systems are in open communication by way of the neural venous sinuses and the lumbar venous plexus. The two wide sinuses accompanying the spinal chord would appear to have the function of reservoirs, since they do not drain any organ or region of the body, but receive blood from the main venous channels of the body. In whichever direction the blood flows in the sinuses it reaches the heart. 3. There is an increasingly generous blood supply to the intercostal muscles pro- ceeding forwards. The two anterior pairs of intercostal spaces have no direct arterial supply or venous drainage, but are in close contact with the capillaries of the thoracic rete. 4. The thoracic rete is innervated by the somatic and sympathetic nervous systems and the basicranial apparently by the trigeminal nerve only. The function of the retia would seem to be the retention of blood. They are blood reservoirs but they do not interfere with the blood supply to or from any part. That the retia were reservoirs of this sort was the suggestion of Hunter (1787, pp. 371-459), Breschet (1836, pp. 1-82) and Owen (1868, vol. in, pp. 545-6). These authors believed, however, that the structures are used for the distribution of arterial blood to the general DISCUSSION 357 circulation during periods when ordinary respiration is suspended, and that the blood so distributed acts in lieu of freshly oxygenated blood from the lungs. The blood from the retia, however, does not, as has been seen, empty into the general arterial circula- tion, but immediately into the venous system, whence it returns to the heart by way of the posterior thoracic vein or neural sinuses from the thoracic rete, and by way of the jugular vein from the basicranial rete. Further, the blood in the thoracic rete at any rate is more venous than arterial. Turner (1872, p. 233) suggested that the rete serves for the retention of blood on its course to certain delicate organs, such as the brain and spinal cord, thus equalizing and distributing the blood stream to these organs and preventing their engorgement. Such an apparatus is seen in the intracranial arteries of ruminants and in the arteries of the human pia mater. However, the arteries which lead through the rete do not serve the brain or spinal chord or, indeed, any delicate organs, but continue somewhat diminished in size to the dorsal musculature, or to the sides of the face, and the flow of blood is not impeded or distributed by the rete. It is certain, nevertheless, that the rete has some fairly intimate relation with the nervous system, since it enwraps the spinal chord at its anterior extremity and spreads out over the hinder surface of the brain. Murie (1873, PP- 290-1) believed the retia to have a physiological function connected with nutrition. " Their office is equivalent to modified blood glands in some way related to pabulum or nutrient fluid. The Retia Mirabilia in Cetacea and other mammals are not confined to the cerebro-spinal tract and neighbourhood of the respiratory apparatus but principally follow lines where lymphatics and absorbents occur in the greatest profusion. Moreover in Cetacea, Sirenia 1 , and Phocidae, where the Retia are most manifest, the lymphatics are unusually abundant and of large size. I apprehend that countless divisions, by coming into close contact with the lymphatic system, conduce to an interchange or exudation of their contents." Murie's theory is based on the similarity of position of the lymphatics and the tracts of vascular tissue similar to that already described in the inguinal region. The theory may well apply to these plexuses, but cannot hold for the thoracic and basicranial retia, where no lymphatic glands were found in relation with the vascular masses. The retia mirabilia, or structures like them, are found in all mammals which are capable of diving and of remaining under the surface for long periods — that is in seals, porpoises, dolphins and whales. According to Owen the littoral and herbivorous Sirenia, which have not the habit of remaining so long submerged, do not possess these vascular networks. It seems reasonable, then, to connect the presence of these blood reservoirs with the capacity for making long and frequent dives. It is well known that whales dive to considerable depths, but little or nothing is known of the actual depths they may reach. It is usual for a Blue or Fin Whale, when pursued, to make repeated dives of anything up to twenty minutes' duration. These long dives are known as "sounds". When the whale is progressing normally, surface 1 According to Owen (1868, p. 547) the Sirenia do not possess thoracic or myelonal plexuses. 358 DISCOVERY REPORTS dives are made which are neither so long nor so deep as the sounding dives. A number of these shallow surface dives always intervenes between two "sounds". Although the usual duration of a " sound " is between ten and twenty minutes, conversations with Norwegian gunners have revealed instances of longer dives than this. The Greenland Right Whale is said to be able to make sounding dives lasting up to forty-five minutes. As to the depths to which whales may descend when sounding very little indeed is known. Scoresby, jun. (1820, p. 468), stated that the Greenland Right Whale has been known to reach eight hundred fathoms. Such a depth, however, is extremely im- probable. Racovitza (1903, pp. 17-19) considers that, when all factors have been taken into account, 100 metres is the maximum depth attainable. It is probable that the depths which whales can reach have been greatly overestimated in the past and that observers have taken the long periods of submergence to imply great depth. The limiting factor in any dive is the danger of caisson disease (liberation of nitrogen bubbles in the blood and tissues, especially the nervous tissues) upon returning suddenly from depths where the excess hydrostatic pressure is greater than 1-25 atmospheres (2-25 atmospheres absolute pressure). Human divers can descend to a depth where this pressure obtains (about 42 feet or 7 fathoms) and return to the surface with impunity ; but at greater depths, involving greater pressures than this, precautions for the pre- vention of caisson disease must be taken, depending on the duration of the exposure to the increased pressure (Boycott, Damant and Haldane, 1908, p. 359). At a depth of 60-66 ft. (3 atmospheres pressure) a human diver can remain for a quarter of an hour, provided that his ascent to the surface occupies two minutes. He can remain at 96- 108 ft. for a similar period, provided he takes in all 11 minutes to reach the surface (with a stop of 3 minutes at 20 ft. and 5 minutes at 10 ft.). At this depth the absolute pressure is 4 atmospheres. There is no a priori reason to suppose that a whale is less susceptible to caisson disease than any other mammal, but we may believe that it has become accustomed to slightly higher pressures, longer exposure, and to returning from these depths rather more quickly than a human diver. Even so it seems improbable that any organism could withstand the effects of swift release from pressures greater than 5 atmospheres — corresponding to a depth of 132 ft. It may be said, then, that a whale probably does not descend to depths much greater than 130 feet, but can remain below for periods of up to half an hour. In considering the effects of diving upon the physiology of the whale, the purely mechanical action of hydrostatic pressure can probably be discounted as a factor. In any case the purely mechanical effects of pressure during a dive are very slight. Animals under observation have been submitted to pressures of nearly 40 atmospheres and have apparently suffered no inconvenience (Report to the Admiralty of a Committee on deep-water diving, p. 1 1), while men in caissons can work freely at depths of 15 fathoms (about 4 atmospheres pressure) provided that ventilation is adequate. The pressure, however, during the dive will have a certain effect in increasing the partial pressure of the oxygen in the lungs. Paul Bert found that for a series of animals and birds oxygen became toxic at a partial pressure of 4 atmospheres. This partial pressure, however, corresponds to 15-20 DISCUSSION 3 59 atmospheres absolute pressure, or a depth of about 2000 ft., and it is impossible that a whale could ever reach such a depth. The chief effects of the dive which must be considered, therefore, are those which arise from its duration rather than from its depth. The main result of a long period of submergence will be that the tissues will acquire a considerable oxygen debt. The chief difficulty, in fact, with which the whale will be confronted during the dive will be that of obtaining, or of taking down, sufficient oxygen for a submergence of twenty minutes to half an hour. At rest a man uses 220 c.c. of oxygen per minute and under conditions of moderate exercise about 500 c.c. Assuming that the total amount of air in the lungs at any moment is 7 litres (1-5 litres of oxygen) there would be enough oxygen in the lungs at any moment to last for three minutes of moderate exercise or 25 seconds of strenuous exercise. Thus if the whale's metabolism is in any way comparable with that of a man he will need to take down, when diving for half an hour, a store of oxygen at least twenty times greater than the amount the lungs could contain at the moment of submergence. It is known, however, that provided the brain and nervous system are kept supplied with oxygen, a man may incur a debt in his tissues equal to ten times the amount of oxygen in the lungs — that is 15 litres, or enough for 30 minutes' moderate exercise and about 4 minutes' strenuous exercise. All attempts to ascribe a function to the vascular networks described in this paper must necessarily be purely speculative. It is fairly evident, however, that all theories which attribute to the retia the function of counteracting the effects of hydrostatic pressure on the distribution of blood in the body and on the circulation generally are without value. Hydrostatic pressure probably makes no difference to the circulation at all, since it is equally distributed within and without the body. The networks are far more likely to be concerned in some way with gaseous exchange, especially as they are present in seals and porpoises, which do not dive to great depths but can remain submerged for long periods. In this connection the situation of the networks near the respiratory centre and on the course of the main blood vessels and also around the brain and nerve chord is extremely suggestive. It has already been mentioned that the masses of the rete are abundantly charged with fat. Oxygen is very soluble in fats. In a table of solubilities of oxygen in a selection of animal and vegetable oils Lewko- witsch (1904, chap, vii) gives the oxygen absorption of whale oil, as shown by Livache's method with lead, to be considerably higher than that of any other oil. The figures are as follows : After 3 days' exposure at N.T.P. 100 parts of cod liver oil absorb 6-382 2 whale oil „ 8-266 sperm oil „ 1-629 Japan fish oil „ 8-194 The oxygen absorption of whale oil is thus nearly half that of ordinary blood. These figures are only given to show that the fatty tissues of the whale's body, and perhaps the fatty masses of the retia mirabilia in particular, are capable of absorbing com- paratively large quantities of oxygen, but it is not suggested that they have any other 3 6o DISCOVERY REPORTS value in the present discussion 1 . It may be imagined that some chemical mechanism exists for a more speedy transfer of oxygen from the blood to the fatty masses of the retia, which may thus act as an oxygen storage mechanism. The retia may in fact be capable of forming a sort of accessory lung. Since the vascular networks are under the control of the somatic nervous system, they may possibly be engorged with blood at will from the posterior thoracic artery, and this blood may perhaps be discharged at will again into the posterior thoracic vein. The proximity of the retia to the heart is extremely suggestive in this connection, since it implies that the blood has only a short distance to travel before reaching the fatty masses where it is to be stored. Thus during the successive inspirations which the whale takes at the surface before sounding, the blood discharges oxygen into the fat of the rete, and this oxygen is subsequently liberated into the circulation during the period of submergence. It has already been remarked that a greatly increased oxygen debt can be incurred in the tissues if the brain and nervous system are kept supplied with oxygen. It is possible that the rete may form, by means of its oxygen-charged fatty masses on the anterior part of the spinal chord and around the hinder part of the brain, a means of keeping the main nervous centres supplied with oxygen during submergence. The basicranial rete may be looked upon as a secondary oxygen reservoir for blood destined for the side of the head, face and orbit. According to this theory of the functions of the retia mirabilia it may be imagined that during submergence blood returns to the heart, not through the postcava, but through the intraspinous veins and the two great sinuses in the neural canal. Thus venous blood from all parts of the abdomen and hinder extremities is made to pass through the thoracic rete into the posterior thoracic vein. It thus enters the right auricle after having been re-oxygenated in the rete. It might be expected that if this actually takes place, and the heart, as a result of this process, receives already oxygenated blood in the right auricle, some mechanism would exist for "short circuiting" the pulmonary artery. No mechanism was found in the Fin Whale except that the ductus arteriosus is very wide and has a spacious lumen. It might easily be imagined to lead blood from the right ventricle into the systemic arch. Lacoste and Baudrimont (1926, pp. 1148-50) found annular folds in the muscular walls of the pulmonary artery of Delphinus delphis, which, the authors suggested, might have the effect of impeding the flow of blood in that artery when fully erected in its lumen. Similarly the small intra- pulmonary branches of the artery "se pulverisent en bouquets extremement touffus d'arterioles tres onduleuses" the effect of which would also be to block the flow of blood through the lungs. 1 Sir Sidney Harmer has drawn my attention to the view held by many whalers and accepted by some writers that the Sperm Whale descends to especially great depths. If this opinion is based on the duration of the "sounds" which the Sperm Whale makes, we should expect to find in the oil of this species a high oxygen solubility. The results tabulated on page 359 show, however, that the solubility is decidedly lower than in other whales. The retia of the Sperm Whale were not examined in detail, but a superficial inspection indicates that they are of even greater extent than in the Fin Whale. They can be seen within the thorax as far back as, I think, the 8th rib. This might be expected if the oxygen solubility of the oil of this species is less than that of Fin Whale oil. SUMMARY 361 The fact, mentioned above, that the first and second intercostal spaces are not supplied with blood from intercostal arteries or drained by veins, seems to be in ac- cordance with this theory of the functions of the retia mirabilia. The first and second intercostal spaces are in intimate contact with the fatty masses of the rete. They are thus closely related to a source of oxygen supply during the long period of sustained contraction during submergence. SUMMARY 1. A description has been given of the retia mirabilia from the dissection of two Fin Whale foetuses, o-86 metre (male) and 1-73 metres (female) in length. 2. The thoracic rete is a fatty vascular mass lying at the anterior end of the thorax and the base of the neck in the fork of the scalenus and rectus capitis anticus major muscles. It is in contact with all the vertebrae from the first and second cervical to the fifth and sixth dorsal. It extends between their transverse processes up into the neural canal through the large foramina between the neural spines. A further vascular mass has been found lying against the basis cranii close to the tympanic bulla. In the cervical region the neural canal of the vertebral column is filled with a dense venous plexus. 3. These vascular masses surround certain blood vessels, but do not block either their arterial or venous channels. The vessels which the thoracic vascular mass surrounds are the ascending branches of the posterior thoracic artery and the intraspinous veins descending from the large neural sinuses to the posterior thoracic vein. The basicranial vascular mass surrounds the cervico-facial artery and drains into, but does not surround, the pterygo-maxillary vein. 4. The postcaval and precaval venous systems in the Fin Whale have been found to be in wide communication by means of a pair of sinuses in the neural canal of the vertebral column, accompanying the spinal chord. There is a large venous plexus in the lumbar region which probably facilitates this communication. 5. The intercostal blood supply has been described to show: (i) That it is derived from four sources as follows : internal mammary arteries and veins, azygos veins and segmental arteries, posterior thoracic arteries and veins, and the thoracic rete. (ii) That the blood supply to the intercostal spaces becomes increasingly generous, proceeding in a rostral direction until the first two intercostal spaces are reached. These have no direct vascular supply, but are overlaid by the rete. (iii) That the return of blood from the intercostal muscles behind the 7th rib is effected by a pair of small veins, thought to be homologous with the azygos veins of other mammals. (iv) That the posterior thoracic arteries and veins of the Fin Whale are probably homologous with the superior intercostals of other mammals. 362 DISCOVERY REPORTS 6. The relation of the retia mirabilia to the nervous system has been described. The thoracic rete is innervated both from the somatic (spinal) and from the sympathetic systems. The basicranial rete is innervated from the trigeminal nerve. 7. The possible function of the retia mirabilia has been discussed. It has been suggested that they act as a kind of accessory lung : the fat absorbs oxygen from the blood during progression at the surface, the oxygen returning into the circulation during submergence. The work on which this paper is based was carried out at the Marine Biological Station of the Discovery Investigations, South Georgia, during the southern summer 1929-30. I wish to thank Sir Sidney Harmer, Dr J. F. G. Wheeler, Professor J. Barcroft, Professor A. V. Hill and Dr C. G. Douglas for valuable suggestions, and for the interest they have shown in the subject. LIST OF LITERATURE Bouvier, E. L., 1889. Les Cetaces Souffleurs. These presentee au Concours d'Agregation du i er Mai, 1889, pp. 92 et seq. (Ecole Superieure de Pharmacie de Paris.) 4to. Lille. Boycott, A. E., Damant, G. C. C. and Haldane, J. S., 1908. The Prevention of Compressed Air Illness. Journ. Hyg., vm, No. 3, pp. 342-444. Breschet, G., 1836. Histoire Anatomique et Physiologique d'un Organe de Nature Vasculaire decouverte dans les Cetaces. 4to. Paris. Carte, A. and Macalister, A., 1868. On the Anatomy of Balaenoptera rostrata. Phil. Trans. Roy. Soc. London, pp. 201-61. Daudt, W., 1898. Beitrage zur Kenntnis des Urogenitalapparates der Cetaceen. Jenaische Zeitschrift fur Naturwiss., xxxn, pp. 231-312. Hunter, J., 1787. Observations on the Structure and Oeconomy of Whales. Phil. Trans. Roy. Soc. London, P-37 1 - Lacoste, A. and Baudrimont, A., 1926. Structure des Arteres pulmonaires du Dauphin (Delphinus delphis). (Adaptations a la Resistance a I'asphyxie par submersion volontaire.) C.R. Soc. Biol. Paris, xciv, pp. 1148-50. Lewkowitsch, J. I., 1904. Chemical Technology and Analysis of Oils, Fats and Waxes, 1, chap. vii. Mac- millan, London. Murie, J., 1873. On the Organisation of the Ca'aing Whale (Globiocephalus melas). Trans. Zool. Soc. London, vm, part iv, pp. 235-301. Owen, R., 1868. On the Anatomy of the Vertebrates. Vol. in. Longmans, Green and Co., London. Report of a Committee appointed by the Lords Commissioners of the Admiralty to consider and report upon the conditions of Deep-Water Diving. August, 1907. Racovitza, E. G., 1903. Resultats d'un Voyage du S.Y. Belgica en 1897-8-9. Zoologie, Cetaces, pp. 17-19. Ridewood, W. G., 1922. Observations on the skull in foetal specimens of whales of the genera Megaptera and Balaenoptera. Phil. Trans. Roy. Soc. London, Series B, 211, pp. 209-272. Schulte, H. von W., 1916. Monographs on the Pacific Cetacea. Anatomy of a foetus of Balaenoptera borealis. Memoirs of the American Museum of Natural History, New Series, I, part vi, pp. 388-502, 14 pis. Scoresby, W., 1820. The Arctic Regions, i, p. 468. Edinburgh. Stannius, 1841. Ueber den Verlauf der Arterien bei Delphinus phocaena. Miiller's Archiv. f. Anat. u. Physiol., vm, part iv, pp. 379-402. Turner, W., 1872. An Account of the Great Finner Whale stranded at Longniddry. Part i. The Soft Parts. Trans. Roy. Soc. Edinburgh, xxvi, part i, pp. 197-251, 4 pis. Wilson, S., 1879. The Rete Mirabile of the Narwhal. lourn. Anat. and Physiol., vol. xiv, pp. 377-98. [Discovery Reports. Vol. V, pp. 363-466, Plates II, III, text-figs. 1-39, September, 1932] THE URINO-GENITAL SYSTEM OF THE FIN WHALE (BALAENOPTERA PHYSALUS) WITH APPENDIX THE DIMENSIONS AND GROWTH OF THE KIDNEY OF BLUE AND FIN WHALES By F. D. OMMANNEY, A.R.C.S., B.Sc. (Lond.) CONTENTS PAGE Introduction 3^5 The male genital system External 3 66 Musculature 3°° Internal organs 37 x The Penis 37 1 The corpus cavernosum and corpus spongiosum 374 The terminal cone 377 The musculature of the penis 37° The prostata 3°° The verumontanum 3° x The uterus masculinus 3 02 The testes 3 8 4 The vasa deferentia 3°° Discussion of the position of the testis 3^7 The vascular supply 3°^ The female genital system External 39 1 The mammary glands 394 Musculature 39° Internal organs 399 The clitoris 399 The ovaries 4 01 The ligamentum latum 4 02 The oviduct and ovarian funnel 4°3 The uterus 4°5 The vagina 4°7 The vascular supply 4 10 Nerves of the genital region 4 10 The urinary system The kidneys 4 12 The coverings of the kidney 4 J 5 The structure of the kidney 4*7 The capsules and tubules 4 2 3 The vascular supply 43 J The urinary duct 43& The bladder and ureter 43^ Discussion 439 Summary 443 List of literature 445 Appendix: dimensions and growth of the kidney of Blue whales (B. musculus) and Fin whales (B. physalus) 447 Dimensions of the whole extracted organ Adult whales 447 Foetuses 45° Weight of the kidney 45 r Volume of the kidney 453 Density of the kidney 453 Diameter of the renculi 454 Number of renculi in the kidney 456 Tables 458 Plates II and III following page 466 THE URINO-GENITAL SYSTEM OF THE FIN WHALE (BALAENOPTERA PHYSALUS) By F. D. Ommanney, A.R.C.S., b.Sc.(lond.) (Plates II, III; text-figs. 1-39) INTRODUCTION The urino-genital system of the Cetacea has been frequently described. Hunter (1787) and Rapp (1837) were among the earliest authors to give an account of it. Since these authors wrote, Yves Delage (1885), who described the gross anatomy of a stranded specimen of an adult Balaenoptera musculus (now B.physahis), Turner (1870), Beauregard and Boulart (1882) and Daudt ( 1 898) have given the best accounts of the system. Struthers (1893) described the muscles in the genital region in a paper which has formed the basis of all subsequent accounts. Meek (19 18) and Anthony (1922) also made contributions to this subject, the former dealing with the genital system of Phocaena communis (now P. phocaena) and the latter that of Mesoplodon bidens. Anthony's paper treats the subject comparatively but describes only the male sex. With the exception of Anthony's paper, however, there is a scarcity of clear figures in the literature of this subject, so that a still further contribution will not be out of place if it does no more than make good this deficiency. In some of the earlier descriptions the material used had evidently been long preserved in formalin and seems to have under- gone distortion. This is especially noticeable in Daudt's paper. During the course of the work the author was particularly struck by certain primitive and distinctive features in the urino-genital system of the Fin whale. An attempt has been made in what follows to emphasize these points and to consider them compara- tively with relation to the conditions found in other orders and sub-orders of Mammalia, with a view to making deductions, if possible, concerning the relationship of the Cetacea to other mammals. The material upon which this work was carried out consisted of four fin whale foetuses — two males 2-65 and 1-23 m. in length and two females 2-1 and 173 m. in length. Dissections of these were made at the Marine Biological Station at South Georgia during the southern summer of 1930-1. A great many kidneys were extracted during work on the flensing platform. These were measured and examined in the laboratory and form the basis of the account of the kidney and the tabulated measure- ments at the end of this paper. The author wishes to thank Sir Sidney Harmer, K.B.E., F.R.S.,and Dr J. F. G. Wheeler, late of the Discovery Investigations, for valuable help and advice and also Mr E. R. Gunther, of the Discovery Investigations, for useful criticism. 366 DISCOVERY REPORTS THE MALE GENITAL SYSTEM EXTERNAL Since the testes are abdominal the only part of the generative system which is visible externally in the adult is the smooth tapering penis (Plate II, fig. i), which is normally withdrawn into a slit-like pouch in the ventral abdominal wall. In mature Fin whales the penis varies in length from 2-o to 2-5 m. (Mackintosh and Wheeler, 1929, p. 380), while in immature whales it is usually nearer i-om. When the penis is completely withdrawn only the genital slit can be seen. The slit lies in front of the anus, the distance between the centres of the two openings being equal to about 6-7 per cent of the total length of the body (Mackintosh and Wheeler, 1929, p. 324). The deep genital slit is usually accompanied by a set of short converging grooves. Two of these, the most pronounced, lie immediately behind the slit (Plate II, fig. 1) and converge towards a point on the mid-ventral line of the body about half-way between the anus and the genital slit. Two others flank the slit and converge anteriorly. A raphe, more distinctly seen in the foetus, runs from the posterior side of the root of the penis along the skin in the middle line to the anus. It is a character common to all Cetacea that in the adult and in later foetal life the penis is, except in the erected condition, withdrawn into such a pouch with swollen lips on the ventral surface of the abdomen. In the stallion also the penis is withdrawn into a very similar pouch of skin. There seems to be some confusion in the literature with regard to the correct term for this slit and for the various parts of the penis. The penis is smooth and tapering, with a conical terminal portion, occupying about one-third of its length, at the apex of which the urethra opens. Around the base of the cone there is a slightly raised fold of integument. The confusion in the terminology seems to have arisen from the fact that the various authors have described the penis in different states of contraction and to the doubt which exists whether the conical terminal part is a true glans or not. Eschricht (1849, P- 81) held the conical terminal portion to be a true glans, and therefore considered the ring-like fold of skin at the base equivalent to a praeputium. Beauregard and Boulart (1882, pp. 169-75), who did not consider the terminal portion to be a true glans, speak of the genital slit as " a sort of praeputial sac ". In one of the two Phocaena embryos and a Beluga embryo described by Daudt (1898, pp. 243-5) the genital slit was not yet developed and the penis was apparently free on the abdominal wall. This author appears to apply the term " preputium" to the whole of the sheath of skin surrounding the penis as far as the base of the terminal cone. He placed the same interpretation upon the structures observed in Balaenoptera (p. 289). Daudt wrote "the point of involution (Umschlagstelle) of the pseudopraeputium " — that is the ring of skin around the terminal cone — "is recognizable in a fully everted penis as a slight ring-like protuberance. If the shaft is inverted the pseudopraeputium disappears but is represented by the whole penis sac". [The "penis sac — Penistasche" — was Weber's term (1904, p. 260) for the genital slit.] In this paper it is proposed to adopt Eschricht's interpretation and to call the ring-like MALE GENITAL SYSTEM: EXTERNAL 3 6 7 fold of skin at the base of the terminal cone a "praeputium" and to reserve the term " penis sac " for the genital slit. The reasons for this will be stated when the homologies of the terminal cone are discussed. The "penis sac", into which the penis is normally withdrawn in the adult, does not make its appearance until fairly late in foetal life. In foetuses less than about 3 m. in length the penis projects free upon the surface of the abdomen. In the smaller of the two foetuses examined in the present work (1-23 m.) the penis was quite free and no sign of the penis sac was to be seen. In the larger foetus (2-65 m.) the sac was foreshadowed by a distinct triangular insinking of the body wall in front of the penis, forming a sort of socket into which the organ fitted. It may thus be assumed that the penis sac is a secondary feature of the genital system of the Cetacea. In the stallion the penis is retractile into a similar fold of skin by means of a pair of retractor muscles, as in the Cetacea. In some Marsupials, some Insectivora, Felidae, Elephas and Tylopoda (Weber, 1904, p. 260) the penis lies in a sac, which, however, also includes the anus and is surrounded by a sphincter cloacae. The penis in these animals emerges backwards and becomes turned forwards during erection, so that no comparison can be drawn between them and the Cetacea. At a point situated about two-thirds of the distance from the base of the penis to the anus, opposite the caudal extremities of the posterior genital grooves, is a pair of small lateral pits. In the foetus 1-23 m. in length they were i-o cm. apart. These are the rudimentary male nipples. In the foetus 2-65 m. long they had nearly disappeared and were seen only as a pair of very shallow depressions 9-0 cm. apart. In the adult they are absent. Sections failed to reveal any trace of glandular structure in the pits except for a slight vascularity of their walls. The male mammary apparatus appears less developed in Balaenoptera physalns than in B. rostrata, where, according to Kiikenthal (1893, p. 356), the male nipple develops as far as the formation of a mammary sac, such as is found in the female foetus during the development of the nipple. Later the sac is reabsorbed in the male. In the Porpoise, however (Kiikenthal, 1893, p. 356), the male nipple rudiment still exists in the adult and its development proceeds yet a step further. A papilla forms at the base of the sac. In Platanista gangetica a sphincter develops around the opening of the sac. The following are the measurements of the external genitalia of the two male Fin whale foetuses dissected. Length of body (tip of snout to notch of flukes) ... 2-65 m. 1-23 m. Length of penis (base to tip) 14-7 cm. 475 cm. (partly retracted) Diameter of penis at base 3-0 cm Diameter of penis at praeputium 1-2 cm. Distance from the base of the penis to anus ... 15-3 cm. 8-o cm Distance from the base of the penis to the mid- point between the nipples 101 cm. Distance between the nipples o-o cm. 3-0 cm. i-o cm. 368 DISCOVERY REPORTS MUSCULATURE An excellent account of the general musculature of the region has been given by Schulte (19 1 6), who described a foetal Sei whale (Balaenoptera borealis), and it is not intended here to do more than give a brief outline of the main muscles based on Schulte 's account. The panniculus carnosus is a thin sheet of muscle fibres belonging to the dermal series, extending over the whole anterior and middle part of the body beneath the blubber layer, but forming a fibrous sheath upon the pedicle behind the anus. The pannicular layer is thickest and most pronounced in the ventral abdominal region and over the cavum ventrale. A latero-dorsal aponeurosis towards which the fibres of the panniculus are directed divides them into a ventral and a dorsal series. The fibres of the dorsal series are directed almost vertically downwards towards this aponeurosis, while those of the ventral series pass upwards somewhat more rostrally from their origin in the mid- ventral line. Around the umbilicus the origins of the ventral series on each side separate, leaving a gap which admits the structures of the umbilical cord. The panniculus is not continued on to the umbilical cord itself. Immediately in front of the base of the penis the panniculus forms a thick muscular mass which is continued on to the organ and forms a muscular sheath in its proximal extremity. This mass is interposed anteriorly between the base of the penis and the rectus abdominis muscle. The obliquus internus muscle is a fair-sized sheet with rostro-ventrally directed fibres arising in the lumbar region from the latero-dorsal aponeurosis already mentioned. At the dorsal margin of the rectus abdominis the obliquus internus divides into two sheets. These become fibrous and form a sheath for the rectus. The superficial sheet is inserted upon the linea alba, and the deep layer is aponeurotic upon the sheath of the rectus muscle internally. The more rostral fibres of the deep layer are inserted upon the caudal margins of the cartilages of the last seven ribs close to the slips of origin of the rectus (Schulte). In its central and caudal portions at any rate, the rectus abdominis is thus enclosed in a fibrous sheath derived from the forking into two layers of the obliquus internus. Schulte states that dorsally the aponeurosis of the transversalis (a thin horizontally directed sheet dorsal to the rectus) is concerned in the formation of this sheath. The rectus abdominis forms a thick mass on the venter of the abdomen, the fibres running rostro-caudally. The linea alba, formed in the mid-ventral line by the fusion of the sheaths of the recti of the two sides, separates the rectus muscle of each side from its antimere. At the umbilicus the two muscle masses diverge to admit the cord so that the muscle fibres are not continued upon it. In the posterior part of the abdomen, immediately in front of the penis (or vulva in the female), the separation of the recti of the two sides becomes very pronounced and a triangular gap is left filled with fibrous tissue and roofed, ventrally, by a thick muscle mass derived from the panniculus. Lateral to the inguinal region the rectus has three terminal insertions. The smallest and MALE GENITAL SYSTEM: MUSCULATURE 3 6 9 least important of these is the insertion upon the ectal border of the rudimentary pelvis (iliac portion, Fig. i / 2 ). Of the two main terminations the superficial one is a triangular wedge of muscle which thins out upon the fibrous fascia between the hypaxial muscle and the origin of the ischio-caudalis. It thus forms a lateral wedge bounding the external genital structures (Fig. i / 3 ). The third and main insertion of the rectus upon the chevron bones can only be seen when the main body of the rectus and the rudi- mentary pelvis are drawn aside (Fig. i I 1 ). The fibres of this deep portion of the muscle run dorsally and caudally to be inserted upon the anterior chevron bones. The insertion of the rectus caudally is thus threefold. Between the deep and superficial parts of this insertion (that is between the portion inserted upon the chevron bones and the iliac portion) a foramen is left through which nerves and blood vessels obtain admission to the penis (and to the clitoris in the female). The transversalis muscle has already been mentioned. It is a thin transverse sheet passing dorsal to the rectus muscle between the latero-dorsal aponeuroses of opposite sides of the body. Its extent is about the same as that of the obliquus internus. The ischio-caudalis (Fig. i / 5 ) is a broad but thin sheet on each side of the mid-ventral line in the caudal region. Dorsally it is bounded by the deep portion of the hypaxial muscle and laterally by the superficial part. In the middle line the antimeres of the two sides are separated by a thin raphe as far forward as the anus, where they diverge to give passage to the rectum (Fig. i o). Anteriorly the ischio-caudalis muscles of each side arise extensively by their lateral fasciculi from the inner sheath of the rectus abdominis and by their inner fasciculi from the ectal margin of the ischial portion of the pelvis. The fibres of the ischio-caudalis extend inwards and caudally and are inserted (Schulte) upon the tips of the chevron bones as far back as the junction of the pedicle with the flukes. Between the ischio-caudalis and the hypaxial muscle, opposite the tip of the triangular insertion of the rectus, a large lumbar vein from the surface of the pedicular region is admitted, running forwards and inwards to its junction with the iliac vein (Fig. i & 3 ). No artery accompanies this vein, but there is a stout lumbar nerve running with it from the main genital nerve from which it arises in the inguinal region. Anteriorly the ischio-caudalis of each side diverges from its antimere to give passage to the anus and rectum. From the anus forward to the penis the ischio-caudalis muscles are separated by a transverse sheet of muscle — the levator ani (Fig. i / 4 ). This muscle is fairly thin in the male but considerably thicker in the female. It takes origin from the deep surface and inner border of the ischio-caudalis and its fibres are continued on to the base of the bulbus penis of the male and the walls of the vulva of the female (Fig. 1 1 /). The antimeres of opposite sides are united in the mid-ventral line below the rectum by a raphe. Schulte describes the levator ani as taking origin anteriorly from the ental surface of the pelvis, but this was not confirmed. A small transverse muscle, the coccygeus, was found behind the anus (Fig. i Z 11 ). The hypaxial muscle (Fig. i /«) is an immense mass extending throughout the whole length of the body ventral to the transverse processes of the vertebral column and occupying, in the lumbar and pedicular regions, the space between the transverse MALE GENITAL SYSTEM: INTERNAL ORGANS 37i processes and the bodies of the vertebrae. Against its extensive surface lie the kidneys and the generative tract, the intestine and rectum and the aorta and postcavae, which are interposed between the muscle masses of opposite sides. In the lumbar and pedi- cular region the hypaxial muscle is divided into two tracts — a deep portion against the bodies of the vertebrae and the transverse processes, and a superficial portion more ventrally abutting on the hypapophyses of the vertebrae. The transversarius muscle occupies the region of the transverse processes laterally. For its origins and insertions and for further details of those of the muscles of this region see Schulte, 1916, pp. 426-7. INTERNAL ORGANS The penis The smooth tapering penis is enclosed as far distally as the praeputial fold by a musculo-fibrous sheath (Figs. 2 e, 3 e). The muscular elements in this sheath are pro- nounced proximally and form a moderately thick circular layer derived from the panni- culus carnosus. Distally these muscles give place to fibres directed circularly around the shaft of the organ. The penis may be considered to consist of two parts, an external part comprising the main shaft of the organ together with the conical terminal part, and an internal portion not visible externally where the shaft of the organ swells out to form the bulbus penis. In the adult and later foetal life the external part is retractile into the "penis sac". Although in young foetuses the "penis sac" is not developed the retractor muscles are yet capable of action and, in preserved specimens at any rate, are in a state of contraction causing an artificial shortening of the external part of the organ and the formation of a circular collar of skin into the middle of which the terminal cone is pulled down. In the Fig. 1. Internal genitalia of a male Fin whale foetus 2-65 m. in length. a. Kidney. I 2 . Iliac attachment of rectus abdominis muscle. b. Plica diaphragmatica. P. Superficial attachment of rectus abdominis c. Caput epididymis. muscle. d. Testis. P. Levator ani muscle. e. Cauda epididymis. P. Ischio-caudalis muscle. /. Vas deferens. / 6 . Hypaxial muscle. g. Ligamentum latum. P. Ischio-cavernosus muscle. h. Ureter. P. Retractor penis muscle. i. Genital cord (mesorchiagos). P. Ischiac attachment of ischio-cavernosus muscle. j 1 . Hypogastric artery. / 10 . Bulbo-cavernosus muscle. j 2 . Epigastric artery and vein. I 11 . Coccygeus muscle. j 3 . Pudic artery. m. Inguinal lymph glands. /*. Cavernous arteries and veins. n. Pelvic rudiment. k 1 . Iliac vein. 0. Rectum. k 2 . Large subsidiary vein in inguinal plexus. p. Anus. k 3 . Lumbar vein. q. Bladder. A*. Pudic vein. r. Terminal cone of penis. I 1 . Caudal attachment of rectus abdominis muscle. 5. Pannicular sheath of penis. Fig. 2. Longitudinal horizontal section of penis of Fin whale. a. Terminal cone. g. Crus corporis cavernosi. b. Retractor penis muscles (cut). /;. Triangular ligament. c. Corpus spongiosum urethrae. i. Bulbo-cavernosus muscle. d. Shaft of corpus cavernosum penis. /. Interpelvic ligament. e. Pannicular sheath of penis. k. Rectum. /. Ischio-cavernosus muscle. A, B, C, D, E, F, G, H and /. Levels of transverse sections in Fig. 4. MALE GENITAL SYSTEM: INTERNAL ORGANS 373 larger of the two foetuses examined (2-65 m.) the external portion of the penis was fully extended, and the ratio of its length to that of the internal part was 1-3 : i-o. In the smaller specimen the penis was partially retracted and measured 4-75 cm., while the internal part measured 3-75 cm. The dimensions of the internal part were never seen in the adult, but from external appearances it could not have measured more than about a third of the length of the outer shaft of the organ. IHG F E D C B A k I m n op Fig. 3. Longitudinal sagittal section of penis and genito-urinary ducts in Fin whale. j. Interpelvic ligament. a. Terminal cone. b. Retractor penis muscle. c. Spongy portion of urethra. d. Corpus cavernosum. e. Panniculus carnosus. /. Ischio-cavernosus muscle. g. Crus corporis cavernosi. h. Triangular ligament. i. Bulbo-cavernosus muscle. k. Rectum. /. Prostatic portion of urethra. m. Compressor prostatae muscle. n. Verumontanum with seminal pores. 0. Vas deferens. p. Urinary duct. q. Urinary pore with crista urethrae. r. Rectus abdominis muscle. A, B, C, D, E, F, G, H and /. Levels of transverse sections in Fig. 4. In describing the penis it has been decided to refer to the " anterior " and "posterior " aspects of the organ, and to abandon the terms "ventral" and "dorsal", employed by Daudt and other authors, in view of the central position of the penis in the middle line of the body. Within the body the penis enlarges, as has been already stated, to form a pear-shaped bulbus (Figs. 1, 2, 3). The greatest width of the bulbus is about one-third the extreme 374 DISCOVERY REPORTS length of the penis from the tip to the base of the bulbus. The bulbus forms two rounded bosses at the base of the organ, the whole mass having a pear shape. It contains the forks of the corpus cavernosum (the crus) but the main body of the bulbus consists of a muscular mass — the ischio-cavernosus muscle or erector penis (Figs. 2/, 3/). The corpus cavernosum and corpus spongiosum. Before considering this muscle mass, however, it will be more convenient to describe the corpus cavernosum itself. It forms the main erectile mechanism of the penis and occupies the shaft of the organ from the terminal cone to the centre of the bulbus (Figs. 2, 3 d, g). Distally, where there is a paucity of muscle fibres around the shaft, the corpus occupies the greater part of the diameter of the penis and a transverse section in the distal portion consists almost solely of the corpus cavernosum with its fibrous sheath and accompanying corpus spongiosum (Fig. 4 C, D). Proximally and within the bulbus the corpus is embedded in the muscle masses that surround that part of the organ. The diameter of the portion of the corpus occupying the shaft of the penis decreases uni- formly towards its distal extremity, but the shape of its cross-section varies considerably. In a section across the terminal cone (Fig. 4 A, B, C) the corpus appears distinctly bean-shaped, with an indentation posteriorly towards the corpus spongiosum. The indentation forms a groove admitting the corpus spongiosum, running from near the tip of the terminal cone to the base of the external part of the organ. At the root of the organ, opposite the reflection of the panniculus carnosus on to its sheath, the section of the corpus cavernosum (Fig. 4 D) becomes oval, the long axis of the oval being directed antero-posteriorly. In the middle of the bulbus the corpus cavernosum forks to form the crus (Figs. 2, 4). Within the shaft of the penis there is no sign whatever of any division of the corpus cavernosum into two parts. The arms of the crus are directed postero-laterally and make an angle of about 45 ° with one another. They are directed into the posterior bosses of the bulbus where they terminate. Distally the arms of the crus are nearly circular in cross-section (Fig. 4 G, H, I), proximally they take on an oval outline. The extremities of the crura are attached to the pelvic bones by the interpelvic ligament shortly to be mentioned. In the angle between the crura there is a small medianly projecting lobe of cavernous tissue, forming a backwardly directed tongue abutting upon the urethra at the commencement of the corpus spongiosum (Figs. 2, 4 G, H, a' 2 ). There is thus an undivided corpus cavernosum within the penis having the form of a Y with a main stem occupying the shaft of the organ and the arms directed backwards into the bulbus. The corpus has an outer investment of circular fibres and an extensive inner core consisting of cavernous tissue of the usual structure with abundant fibres and interstitial blood spaces. The following are the measurements in the 1-23 m. foetus: Length of the shaft of the corpus 3-5 cm. Length of each arm of the crus 3-0 Diameter of the centre of the shaft 075 ,, Diameter of the centre of each ramus ... ... 0-5 ,, eu u J3 CO J3 u CO 3 £ •C 3 u bo O S S3 3 o a o co c O C -t- -3 t O, bo T3 h o a, O u S? bo s -a a « *-» CO O Compress Triangula d d *S! ~ '*I| 2 " T3 3