DISCOVERY REPORTS VOLUME XXVIII 7X¥- DISCOVERY REPORTS fy,d»L Issued by the National Institute of Oceanography J-3Z VOLUME XXVIII CAMBRIDGE AT THE UNIVERSITY PRESS 1957 PUBLISHED BY THE SYNDICS OF THE CAMBRIDGE UNIVERSITY PRESS Bentley House, 200 Euston Road, London, N.W.i American Branch: 32 East 57th Street, New York 22, N.Y. Printed in Great Britain at the University Press, Cambridge (Brooke Crutchley, University Printer) CONTENTS MYSIDACEA (published 8th December, 1955) By Olive S. Tattersall Introduction Gear Station Lists Geographical Distribution List of New Genera and Species with Their Localities List of Species in Systematic Order, with Synonymies Systematic Report Report on the First Survey of the Benguela Current Bibliography Index of Species page 3 4 5 J9 23 24 27 182 184 189 THE DISTRIBUTION OF THE STANDING CROP OF ZOOPLANKTON IN THE SOUTHERN OCEAN (published 30th April, 1956) By P. Foxton Introduction page iqt Acknowledgements jo. Material jq. Methods !q6 Seasonal Variation in the Vertical Distribution of the Standing Crop of Zooplankton 200 Regional Variations in the Standing Crop of Zooplankton 213 Comparison with the Findings of Other Workers 223 Summary 22- References 22- Appendix 22q SPERM WHALES OF THE AZORES (published 12th December, 1956) By Robert Clarke Introduction page 23„ Acknowledgements 2ao Material 2,r Size Range 2 . x External Characters 24, Tee™ 249 Parasites 2,-2 Disease, Deformity and Injury 2c. 724;. vi CONTENTS Food page 256 Breeding and Life Cycle 262 Schooling 277 Sex Ratio 280 Distribution and Seasonal Movements 282 Racial Identity of the Stock 286 Condition of the Stock under Whaling 289 Summary 292 References 294 Plates I, II following page 298 STATION LIST 1950-1951 (published 28th February, 1957) Introduction page 300 R.R.S. 'Discovery II', Stations 2653-291 1 303 Summarized List of Stations 398 Plates III-V following page 398 [Discovery Reports. Vol. XXVIII, pp. 1-190, November 1955.] MYSIDACEA 2>. c By OLIVE S. TATTERSALL, D.Sc. %0. / *J°, C&> c^-3' CONTENTS Introduction page 3 Gear Station lists Geographical distribution ..... List of new genera and species with their localities List of species in systematic order, with synonymies Systematic report ...... Report on the first survey of the Benguela Current Bibliography ....... Index of species ....... 5 l9 23 24 27 182 184 189 MYSIDACEA By Olive S. Tattersall, d.Sc. (Text-figs. 1-46) INTRODUCTION Before his death in 1943 my husband, the late Professor W. M. Tattersall, had done a considerable amount of preliminary identification of the very large number of mysids sorted from the collections of the 'Discovery' Investigations, now incorporated in the National Institute of Oceano- graphy. Unfortunately not a single note concerning this work has been found among his papers so that all the counting, measuring and ascertaining the sex and age of the specimens has had to be done again. However, his provisional sorting into genera and, in some cases, into species has been of the utmost help in working on the material. This very rich collection, amassed over a number of years, does not comprise all the mysids in the 'Discovery' collections, for much of the plankton has yet to be sorted, but there are over 5000 specimens, generally in very good condition, from 391 stations which are nearly all situated in the South Atlantic and Southern Ocean. In addition I have included a record of specimens of Boreomysis rostrata Illig, collected in surface tow-nets off the shores of Heard Island, which were sent to me for identification by the courtesy of Dr P. G. Law, Director of the Antarctic Division of the Department of External Affairs, Australian National Antarctic Expedition. This is particularly interesting because I can find no other record of this species from surface waters. Identification of the Mysidacea is made difficult by the fact that, in many of the species, the animals continue to grow long after sexual maturity has been attained. This growth is accompanied by considerable changes in the proportions and armature of the body and appendages, so that smaller individuals differ profoundly from larger ones. This disconcerting phenomenon has led to much confusion in the past, because workers with only a few specimens at their command have frequently founded new species, which have subsequently proved to be different growth stages of species already described. The actual size of the animals is, unfortunately, not a reliable guide because specimens living in warmer waters mature more rapidly and reach the various growth stages at a much smaller size than those inhabiting colder regions. Only when large numbers of specimens of all sizes are available can the gradual growth changes be traced and the true identity of younger individuals of a species be established. Such growth changes are particularly conspicuous in species of the genera Gnathophausia and Eucopia. The Discovery collection contains over sixty specimens (of all sizes) of Gnathophausia ingens and more than thirty of G. gigas. I have made detailed measurements of these species and the results, which I give in tabular form, fully endorse the valuable work in this field done by Ortmann and others. I have also drawn up a list of the species represented in the Discovery collection together with their synonymies, so that when isolated specimens are found they can the more readily be referred to their true species even though they may represent quite young growth stages (see p. 24-27). Another difficulty in working out large collections lies in deciding how much individual variation should be tolerated among members of any one species. In many genera such a mass of slightly differing characters occurs that it seems impossible to find any consistent features whereby the animals can be separated into definite groups. As a result two alternatives arise, (i) making a very 4 DISCOVERY REPORTS large number of new species, or (ii) ' lumping ' them all into one species with a very flexible definition. This problem occurs very markedly in the genera Boreomysis, Pseudomma and Euchaetomera. I have perhaps erred on the side of too much ' lumping ' in these genera and I think that possibly future workers may find satisfactory characters which are sufficiently constant to justify the formation of several new species. I have found little evidence of any correlation between differences in form and geographical distribution for specimens captured in the same areas and even in the same hauls display the same individual variation as those from completely different localities. There does appear, however, to be evidence of a geographical race in a species of Boreomysis captured in the waters around South Georgia. In general form, in the shape of the rostrum and in the characteristic form of the telson, the specimens agree with the descriptions of B. rostrata Illig, but they are distinctly larger and the eyes are nearly twice the usual size found in this species. These characters are so noticeable that the animals can be picked out with the naked eye. I would have founded a new species for them, but for the fact that specimens were present in near-by localities, in which the size of the eyes and the length of adult animals were intermediate between those of the normal B. rostrata and the large-eyed variety. I have therefore recorded them simply as ' Boreomysis rostrata with very large eyes ' and sug- gested that they may represent a geographical race. A total of thirty-six genera and ninety-five species is represented in the collection. Of these I regard two genera and twenty-eight species as new. A review of past records and, in some cases, an examina- tion of material from other collections has made it necessary to change the names of one or two species, but this has only been done where absolutely necessary and full explanations are given in the text. In this connexion I should like to express my gratitude to Dr Waldo L. Schmitt of the Smithsonian Institution, Washington, for most generously lending me some specimens of a very rare and interesting mysid for comparison with some of the Discovery material and to Dr Isobel Gordon of the British Museum for allowing me to examine so many of the valuable collections in her care. While this work was in progress I received a small supplementary collection of Mysidacea taken by R.R.S. 'William Scoresby' during a survey of the Benguela Current in March 1950. Mysids occurred at twelve stations and, although the actual numbers were few, ten genera were represented and sixteen species, one of which is new to science. The records are included in the list of stations of the ' William Scoresby ' and a short account of the collection is added as an appendix to this report. I should like to express my grateful thanks to Dr N. A. Mackintosh, Deputy Director of the National Institute of Oceanography for allowing me to examine this valuable and interesting collection and to tender my warm appreciation and thanks to Dr Helene Bargmann for her unfailing help and en- couragement throughout the course of this work. GEAR Abbreviations used in the list of stations to indicate kind of gear used B, oblique; H, horizontal; V, vertical; BNR, Russell's bottom tow-net; BTS, small beam trawl; DC, conical dredge; DL and DLH, large dredge; DS, small dredge; LH, hand lines; N4-T, N7-T, nets attached to back of trawl; N50, 50 cm. tow-net; N70, 70 cm. tow-net; Nioo, 1 m. tow-net; N200, 2 m. tow-net; N450, 4^ m. tow-net; NC50, coarse 50 cm. tow-net; NCS-D, NCS-T, NCS-N, tow-net attached to dredge, trawl or other net; NRL, large rectangular net; NRM, medium rectangular net; OTL, large otter trawl; TYF and TYF70 B, young-fish trawl. Where the depth of termination of an oblique haul is written '(-o)' it must be understood that the net failed to close at some intended intermediate depth and fished all the way to the surface. The last part of the haul from the intended depth of closing to the surface would usually occupy a small fraction of the total time of fishing. STATION LISTS 5 LIST OF STATIONS AT WHICH MYSIDACEA WERE COLLECTED WITH THE SPECIES OBTAINED AT EACH STATION R.R.S. 'DISCOVERY I' AND R.R.S. 'DISCOVERY II' ft. x. 25. 29" 27' N., 15° 07' W. From stomach of Naucrates doctor, 900-0 m. : Euchaetomera typica G. O. Sars. 10. x. 25. 41° 37' 15" N., 120 36' 20" W. Net 2 m. 900-0 m. : Gnathophausia ingens (Dohrn); Eucopia sculpticauda Faxon. 14. x. 25. 340 23' N., 140 32' W. Surface: Siriella thompsonii (M.-Ed.). 28. x. 25. 130 25' N., 18 22' W. 900-0 m.: Eucopia unguiculata (W.-Suhm); Eucopia sculpticauda Faxon. 2. xi. 25. 6° 55' N., 150 54' W. N 200. 800-0 m. : Caesaromysis hispida Ortmann; Eucopia unguiculata (W.-Suhm); Eucopia sculpticauda Faxon. St. 9. 11. ii. 26 (day). Midway between Gough Island and South Georgia. N 200. i25o(-o) m.: Gnathophausia gigas W.-Suhm. St. 31. 17. iii. 26 (night). 13-5 miles N. 890 E. of Jason Light, South Georgia. N 100 H. 9o(-o) m.: Antarctomysis maxima (Hansen). St. 32. 17. iii. 26 (night). 22-8 miles N. 700 E. of Jason Light, South Georgia. N 100 H. 9o(-o) m.: Antarctomysis maxima (Hansen). St. 39. 25. iii. 26 (day). East Cumberland Bay, South Georgia. N 7-T. 235-179 m. : Mysidetes posthon Holt and Tattersall; Mysidetes kerguelensis Illig; Mysidetes microps sp.n.; Antarctomysis maxima (Hansen); Antarcto- mysis ohlini Hansen. St. 41 D, St. 41 E. 28. iii. 26 (night). i6i miles N. 390 E. of Barff Point, South Georgia. N 200 V. 100-50 m. : Antarctomysis maxima (Hansen); Antarctomysis ohlini Hansen. St. 42. 1. iv. 26 (day). Off mouth of Cumberland Bay, South Georgia. OTL and N 4-T. 120-204 m. : Boreomysis rostrata var. (with very large eyes) Illig; Pseudomma armatum Hansen; Mysidetes posthon Holt and Tattersall; Antarctomysis maxima (Hansen) ; Antarctomysis ohlini Hansen. St. 45. 6. iv. 26 (day). 27 miles S. 850 E. of Jason Light, South Georgia. OTL, N 4-T and N 7-T. 238- 270 m. : Pseudomma sarsi W.-Suhm in MS. Hansen; Pseudomma armatum Hansen; Mysidetes posthon Holt and Tattersall; Mysidetes microps sp.n.; Mysidetes dimorpha sp.n.; Antarctomysis maxima (Hansen); Antarctomysis ohlini Hansen. St. 49. 3. v. 26 (night). Off Cape Bougainville, East Falkland Is. N 100 H. 0-5 m.: Mysidopsis acuta Hansen. St. 51. 4. v. 26 (day). Off Eddystone Rock, East Falkland Is. NCS-T. 105-115 m.: Pseudomma minutum sp.n. cJ Types ; Pseudomma calmani sp.n. ; Mysidetes crassa Hansen ; Mysidetes intermediasp.n. ; Mysidopsis acuta Hansen. St. 56. 16. v. 26 (day). Port William, East Falkland Is. NCS-T. ioi-16 m.: Mysidopsis acuta Hansen. St. 71. 30. v. 26 (day). North-east of Falkland Is. TYF. 200o(-o) m.: Gnathophausia gigas W.-Suhm; Eucopia grimaldii Nouvel; Boreomysis rostrata Illig. St. 72. 1. vi. 26 (night). North-east of Falkland Is. N 450. 200o(-o) m. : Gnathophausia gigas W.-Suhm. St. 76. 5. vi. 26 (day). Midway between Gough Is. and Bahia, Argentine. N 450. i50o(-o) m. : Gnathophausia ingens (Dohrn); Gnathophausia gigas W.-Suhm. St. 78. 12. vi. 26 (day). Mid-Atlantic, West of Cape Town. TYF. iooo(-o) m. : Eucopia australis Dana; Boreo- mysis rostrata Illig; Caesaromysis hispida Ortmann; Longithorax capensis Zimmer. St. 81. 18. vi. 26 (day). Mid-Atlantic, West of Cape Town. N 450. 65o(-o) m.: Gnathophausia ingens (Dohrn); ? Boreomysis rostrata Illig; Caesaromysis hispida Ortmann. St. 83. 21. vi. 26 (night). North-east of Tristan da Cunha. N 200 V. 65o(-o) m. : Boreomysis rostrata Illig. St. 85. 23. vi. 26 (night). West of Cape Town. N 450. 200o(-o) m.: Eucopia australis Dana; Boreomysis bispinosa sp.n.; Boreomysis sibogae Hansen. St. 86. 24. vi. 26 (day). West of Cape Town. N 450. iooo(-o) m.: Gnathophausia ingens (Dohrn); Gnatho- phausia gigas W.-Suhm; Eucopia unguiculata (W.-Suhm); Eucopia sculpticauda Faxon; Eucopia grimaldii Nouvel; Boreomysis rostrata Illig; Boreomysis bispinosa sp.n. St. 87. 25. vi. 26 (day). West of Cape Town. TYF. iooo(-o) m.: Boreomysis rostrata Illig; Boreomysis illigi sp.n.; Siriella thompsonii (M.-Ed.); Katerythrops oceanae Holt and Tattersall; Meterythrops picta Holt and Tattersall; Euchaetomera typica G. O. Sars. 6 DISCOVERY REPORTS St. 89. 28. vi. 26 (day). Off Cape Town. TYF. iooo(-o) m.: Eucopia unguiculata (W.-Suhm); Eucopia grimaldii Nouvel; Boreomysis rostrata Illig; Boreomysis bispinosa sp.n.; Siriella thompsonii (M.-Ed.); Meterythrops picta Holt and Tattersall; Katerythrops oceanae Holt and Tattersall; Longithorax capensis Zimmer; Euchaetomera typica G. O. Sars; Euchaetomera tenuis G. O. Sars; Caesaromysis hispida Ortmann; Siriella thompsoni (M.-Ed.). St. 90. 10. vii. 26 (day). False Bay, South Africa. NRM. 10-12 m. : Gastrosaccus sanctus (van Beneden); Anchialina truncata (G. O. Sars); Mysidopsis major (Zimmer); Mysidopsis schultzei (Zimmer); Mysidopsis similis (Zimmer); Mysidopsis camelina sp.n. St. 91. 8. ix. 26 (day). False Bay, South Africa. NCS-N. 35 m.: Anchialina truncata (G. O. Sars). TYF. 0-5111.: Mysidopsis schultzei (Zimmer); 35 m., Mysidopsis similis (Zimmer). 12. ix. 26. Walvis Bay (from stomach of Trigla capensis). 4-57 m. : Afromysis hansoni Zimmer. St. 100. 2. x. 26 (day). West of Cape Town. TYF. 450-550 m. : Longithorax capensis Zimmer. 47 5(-o) m., ? Boreo- mysis rostrata Illig; Meterythrops picta Holt and Tattersall; Longithorax capensis Zimmer. 675-625 m., Katery- throps oceanae Holt and Tattersall; Boreomysis rostrata Illig. 3. x. 26 (day). TYF. 310-260 m. : Euchaetomera tenuis G. O. Sars; Caesaromysis hispida Ortmann. 3/4. x. 26 (night). TYF. 1000-900 m. : Gnathophausia ingens (Dohrn); Boreomysis microps G. O. Sars; Boreoinysis rostrata Illig; Meterythrops picta Holt and Tattersall. 4. x. 26 (day). TYF. 250o(-o)m.: Gnathophausia ingens (Dohrn); Eucopia sculpticauda Eaxon; Gibberythrops megalops sp.n. S Type; Euchaetomera tenuis G. O. Sars; Caesaromysis hispida Ortmann. 4. x. 26 (day). TYF. 2500-2000 m.: Gnathophausia gigas W.-Suhm; Eucopia unguiculata (W.-Suhm); Eucopia australis Dana; Boreomysis rostrata Illig; Boreomysis atlantica Nouvel; Euchaetomera zurstrasseni (Illig); Caesaromysis hispida Ortmann. St. 101. 14. x. 26 (night). West of Cape Town. N 450. 2580-2480 m.: Gnathophausia ingens (Dohrn); Chalar- aspidum alatum (W.-Suhm); Eucopia australis Dana; Eucopia sculpticauda Faxon; Eucopia grimaldii Nouvel. 14. x. 26 (day). N450. 1410-1310111. : Gnathophausia gigas W .-Suhm; Eucopia australis Dana; Eucopia sculpticauda Faxon ; Boreomysis rostrata Illig. 15. x. 26 (day). N450. 950-850 m.: Eucopia sculpticauda Faxon; Eucopia grimaldii Nouvel. 15. x. 26 (night). N450. 35o~40o(-o) m. : Gnathophausia ingens (Dohrn). St. 107. 4. xi. 26 (day). South-south-west of Cape Town. N 450. 950-850 m. : Gnathophausia ingens (Dohrn). St. 114. 12. xi. 26 (day). North-east of Bouvet I. N 450. 700-650 m.: Gnathophausia gigas W.-Suhm. St. 120. 22. xi. 26 (day). North-west of Bouvet I. N 100 H. 36o~34o(-o) m.: Euchaetomera zurstrasseni (Illig)- St. 123. 15. xii. 26 (day). Off Cumberland Bay, South Georgia. N 7-T, N 4-T. 230-250 m.: Pseudomma armatum Hansen; Mysidetes posthon Holt and Tattersall; Mysidetes microps sp.n.; Mysidopsis acuta Hansen; Antarcto- mysis maxima Holt and Tattersall; Antarctomysis ohlini Hansen. St. 129. 19. xii. 26 (dusk to dark). Off South Georgia. N 70 V. 950-750 m. : Boreomysis rostrata var. (with very large eyes) Illig. St. 134. 21. xii. 26 (day). South-east of Cumberland Bay, South Georgia. N 100 H. 123 m. : Antarctomysis maxima Holt and Tattersall. St. 138. 22. xii. 26 (day). Off South Georgia. N 70 V. 1000-750 m.: Dactylamblyops hodgsoni Holt and Tattersall. St. 140. 23. xii. 26 (day). Off South Georgia. OTL. 122-136 m.: Pseudomma sarsi (W.-Suhm); Mysidetes microps sp.n.; Mysidetes dimorpha sp.n.; Antarctomysis maxima H. and T. St. 142. 30. xii. 26 (day). East Cumberland Bay, South Georgia. N 7-T, N 4-T. 88-273 m.: Pseudomma armatum Hansen; Pseudomma sarsi (W.-Suhm); Mysidetes posthon Holt and Tattersall; Mysidetes kergueletisis Illig; Mysidetes microps sp.n. ; Mysidetes macrops sp.n. ; Antarctomysis ohlini Hansen. St. 143. 30. xii. 26 (day). Off Cumberland Bay, South Georgia. NCS-T. 273 m. : Mysidetes posthon Holt and Tattersall; Antarctomysis maxima Holt and Tattersall. St. 144. 5. i. 27 (day). Off Stromness Harbour, South Georgia. NCS-T. 155-178 m.: Mysidetes posthon Holt and Tattersall; Mysidetes microps sp.n.; Antarctomysis maxima Holt and Tattersall. St. 146. 8. i. 27 (day). Off South Georgia. DLH. 728 m.: Boreomysis rostrata var. (with very large eyes) Illig; Boreomysis inermis (W.-Suhm). St. 148. 9. i. 27 (day). Off Cape Saunders, South Georgia. N 4-T. 132-148 m.: Pseudomma armatum Hansen; Mysidetes posthon Holt and Tattersall ; Mysidetes brachylepis W. M. Tattersall ; Mysidetes microps sp.n. ; Antarcto- mysis maxima Holt and Tattersall. STATION LISTS 7 St. 149. 10. i. 27 (day). East Cumberland Bay, South Georgia. NCS-T. 200-234 m.: Rhopalophthalmus egregius Hansen; Gastrosaccus sanctus (van Beneden); Pseudomma sarsi (W.-Suhm); Antarctomysis maxima Holt and Tattersall. St. 151. 16. i. 27 (day). North of South Georgia. N 450. 1275-1025 m. : Encopia grimaldii Nouvel; Dactylamblyops hodgsoni Holt and Tattersall. St. 152. 17. i. 27 (day). Off South Georgia. DLH. 245 m.: Mysidetes posthon Holt and Tattersall. St. 154. 18. i. 27 (day). Off South Georgia. N 4-T. 60-160 m. : Pseudomma armatum Hansen; Antarctomysis maxima Holt and Tattersall; Antarctomysis ohlinii Hansen; NCS-T. 60-160 m. : Pseudomma sarsi W.-Suhm; Mysidetes posthon Holt and Tattersall ; Mysidetes microps. Types, sp.n. ; Antarctomysis ohlini Hansen. St. 156. 20. i. 27 (day). Off South Georgia. DLH. 200-236 m.: Mysidetes posthon Holt and Tattersall; Antarcto- mysis maxima Holt and Tattersall. St. 162. 17. ii. 27 (day). Off Signy I., South Orkneys. DLH. 320 m. : Pseudomma armatum Hansen; Pseudomma sarsi W.-Suhm; Antarctomysis maxima Holt and Tattersall. St. 164. 18. ii. 27 (day). Near Cape Hansen, South Orkneys. NCS-T. 24-36 m.: Antarctomysis maxima Hansen in MS. Holt and Tattersall. St. 167. 20. ii. 27 (day). Off Signy I., South Orkneys. N 4-T. 244-344 m. : Pseudomma armatum Hansen; Pseudomma sarsi W.-Suhm; Mysidetes posthon Holt and Tattersall; Antarctomysis maxima Holt and Tattersall. St. 169. 22. ii. 27 (day). West of South Orkneys. TYF. 1100-1000 m. : Dactylamblyops hodgsoni Holt and Tattersall. St. 170. 23. ii. 27 (day). Off Cape Bowles, South Shetlands. DLH. 342 m. : Antarctomysis maxima Holt and Tattersall. St. 172. 26. ii. 27 (day). Off Deception I., South Shetlands. DLH. 525 m.: Mysidetes brachvlepis W. M. Tattersall. St. 181. 12. iii. 27 (day). Schollaert Channel, Palmer Archipelago. N 4-T, N 7-T, NCS-T. 160-335 m- : Hanseno- mysis antarctica Holt and Tattersall; Pseudomma belgicae Hansen; Pseudomma schollaertensis Types, sp.n.; Pseudomma longicaudum Types, sp.n. ; Paramblyops brevirostris $ Types, sp.n. ; Mysidetes posthon Holt and Tattersall; Antarctomysis maxima Holt and Tattersall. St. 182. 14. iii. 27 (day). Schollaert Channel, Palmer Archipelago. N 4-T. 278-500 m.: Pseudomma antarcticum Zimmer; Pseudomma belgicae Hansen; Paramblyops brevirostris sp.n., £ Types; Mysidetes posthon Holt and Tattersall. St. 187. 18. iii. 27 (day). Neumayr Channel, Palmer Archipelago. DLH. 259 m.: Mysidetes posthon Holt and Tattersall; Antarctomysis maxima Holt and Tattersall. St. 190. 24. iii. 27 (day). Bismarck Strait, Palmer Archipelago. DLH. 43 m., 93-126 m. and 315 m. : Antarcto- mysis maxima Holt and Tattersall; Mysidetes posthon Holt and Tattersall. 93-126 m.: Mysidetes dimorpha sp.n. St. 204. 6. iv. 27 (day). Bransfield Strait, South Shetlands, N 70 V. 750-500 m. : Dactylamblyops hodgsoni Holt and Tattersall. St. 205. 6. iv. 27 (day). Bransfield Strait, South Shetlands: Antarctomysis ohlini Hansen. (No depth given.) St. 208. 7. iv. 27 (day). Off Livingstone f ., South Shetlands. TYF. 8oo(-o) m. : Boreomvsis brucei W. M. Tattersall ; Dactylamblyops hodgsoni Holt and Tattersall; Antarctomysis maxima Holt and Tattersall; Antarctomysis ohlini Hansen. St. 239. 2. vi. 27 (day). North-east of South Georgia. N 450. i35o-i05o(-o) m. : Gnathophausia gigas W.-Suhm; Eucopia grimaldii Nouvel; Boreomysis bispinosa sp.n. St. 245. 10. vi. 27 (day). West of Tristan da Cunha. N 450. 2000-1800 m. : Gnathophausia zoea W.-Suhm; Eucopia australis Dana; Boreomysis atlantica Nouvel. St. 250. 17. vi. 27 (night). North-east of Tristan da Cunha. TYF. 30o(-o) m. : Euchaetomeropsis merolepis (IUig). St. 252. 20. vi. 27 (night). East-north-east of Tristan da Cunha. N 100 H. 135 m. : Euchaetomera typica G. O. Sars; Arachnomysis megalops Zimmer. St. 253. 21. vi. 27 (day). North-east of Tristan da Cunha. TYF. 1050-1000 m. : Chalaraspidum alatum (W.-Suhm); Gnathophausia gigas W.-Suhm; Eucopia unguiculata (W.-Suhm); Eucopia grimaldii Nouvel. St. 254. 21. vi. 27 (night). North-east of Tristan da Cunha. TYF. 20o(-o) m. : Euchaetomera zurstrasseni (IUig); Euchaetomera intermedia Nouvel ; Longithorax capensis Zimmer. 8 DISCOVERY REPORTS St. 256. 23. vi. 27 (day). West of Cape Town. TYF. noo-85o(-o) m. : Gnathophaasia ingens (Dohrn); Eucopia sadpticaiida Faxon; Eucopia grimaldii Nouvel; Boreomysis rostra Illig; Siriella thompsonii (M.-Ed.); Katerythrops oceanae Holt and Tattersall; Katerythrops resimora sp.n. Types; Meterythrops picta Holt and Tattersall; Euchaetomera typica G. O. Sars; Euchaetomera tenuis G. O. Sars; Euchaetomera intermedia Nouvel; Caesaromysis hispida Ortmann. St. 257. 24. vi. 27 (night). West of Cape Town. TYF. 25o(-o) m. : Gnathophausia ingens (Dohrn); Siriella thompsonii (M.-Ed); Euchaetomera typica G. O. Sars; Euchaetomera intermedia Nouvel; Euchaetomeropsis merolepis (Ulig)- St. 258. 25. vi. 27 (night). West of Cape Town. TYF. 450-320 m. : Siriella thompsonii (M.-Ed.); Euchaetomera tenuis G. O. Sars; Longithorax capensis Zimmer. St. 259. 26. vi. 27 (night). West of Cape Town. TYF. 450~37o(-o) m. : Longithorax capensis Zimmer; Euchaetomera zurstrasseni Illig; Euchaetomera intermedia Nouvel. St. 266. 21. vii. 27 (night). West of Orange River estuary. TYF. 20o(-o) m. : Longithorax capensis Zimmer; Euchaeto- mera typica G. O. Sars; Euchaetomera glyphidophthalmica Illig; Euchaetomeropis merolepis (Illig). St. 267. 23. vii. 27 (night). Off Angra Pequena. TYF. 550-45o(-o) m. : Boreomysis rostrata Illig; Meterythrops picta Holt and Tattersall; Katerythrops oceanae Holt and Tattersall; Euchaetomera tenuis G. O. Sars; Euchaeto- mera zurstrasseni (Illig); Euchaetomera intermedia Nouvel; Euchaetomeropsis merolepis (Illig); Caesaromysis hispida Ortmann ; Arachnomysis megalops Zimmer. St. 268. 25. vii. 27 (night). West of Cape Frio, South Africa. TYF. i50-ioo(-o) m. : Siriella thompsonii (M.-Ed.); Euchaetomera intermedia Nouvel ; Arachnomysis megalops Zimmer. St. 270. 27. vii. 27 (night). TYF. 20o(-o) m. West of Benguela: Arachnomysis leuckartii Chun. St. 274. 4. viii. 27 (day). Off St Paul de Loanda, Angola. N4-T. 65-64 m. : Rhopalophthalmus egregius Hansen; NCS-T. 65-64 m. : Leptomysis apiops G. O. Sars; Leptomysis megalops Zimmer; Antarctomysis maxima Holt and Tattersall. St. 276. 5. viii. 27 (night). Off Congo River estuary. TYF. i5o(-o) m.: Euchaetomera glyphidophthalmica Illig. St. 277. 7. viii. 27 (night). South of Cape Lopez. TYF. 63(-o) m. : Lophogaster challengeri Fage; Anchialina trun- cata (G. O. Sars); Erythrops africana sp.n. Types; Leptomysis apiops G. O. Sars; Leptomysis megalops Zimmer. St. 279. 10. viii. 27 (day). Off Cape Lopez. NCS-T. 58-67 m. : Lophogaster challengeri Fage; Rhopalophthalmus egregius Hansen; Leptomysis apiops G. O. Sars; Leptomysis capensis Illig. St. 280. 10. viii. 27 (night). Off Cape Lopez. N 100 B. 84-0 m. : Afromysis hansom Zimmer. St. 281. 12. viii. 27 (day). West of Cape Lopez. TYF. 95o-85o(-o) m.: Eucopia unguiculata (W.-Suhm); Eucopia australis Dana; Eucopia grimaldii Nouvel; Eucopia sculpticauda Faxon. St. 282. 12. viii. 27 (night). West of Cape Lopez. TYF. 30o(-o) m. : Euchaetomera typica G. O. Sars; Euchaetomera tenuis G. O. Sars; Caesaromysis hispida Ortmann; Arachnomysis megalops Zimmer; Arachnomysis leuckartii Chun. St. 285. 16. viii. 27 (night). Gulf of Guinea. N 450. i75-i25(-o) m.: Gnathophausia ingens (Dohrn). St. 286. 17. viii. 27 (night). Midway between Cape Lopez and Ascension I. TYF. i25(-o) m. : Euchaetomera typica G. O. Sars. St. 287. 19. viii. 27 (night). Gulf of Guinea. TYF. iooo-8oo(-o) m.: Eucopia australis Dana; Eucopia sculpticauda Faxon; Eucopia grimaldii Nouvel; Boreomysis microps G. O. Sars. St. 288. 21. viii. 27 (night). Gulf of Guinea. TYF. 25o(-o) m.: Gnathophausia ingens (Dohrn). St. 289. 23/24. viii. 27 (night). Gulf of Guinea. TYF. 225~i25(-o) m. : Gnathophausia ingens (Dohrn). St. 290. 24. viii. 27 (dawn). West of Sierra Leone. TYF. ioo(-o) m.: Arachnomysis leuckartii Chun. St. 295. 25. viii. 27 (day). West of Sierra Leone. TYF. 2700-250o(-o) m.: Eucopia unguiculata (W.-Suhm); Eucopia australis Dana; Eucopia sculpticauda Faxon; Eucopia sp. ; Euchaetomera typica G. O. Sars; Euchaetomera tenuis G. O. Sars. St. 296. 26. viii. 27 (night). South-west of Monrovia. TYF. 550-45o(-o) m.: Gnathophausia ingens (Dohrn). St. 298. 29. viii. 27 (day). West of Cape Verde. TYF. i200-90o(-o) m. : Eucopia unguiculata (W.-Suhm); Eucopia sculpticauda Faxon; Eucopia grimaldii Nouvel; Boreomysis illigi sp.n. Types. St. 300. 20. i. 30 (day). North of South Georgia. N 70 V. 750-500 m. : Dactylamblyops hodgsoni Holt and Tattersall. St. 302. 21. i. 30 (day). North of South Georgia. N 70 V. 1000-750 m.: Dactylamblyops hodgsoni Holt and Tattersall. St. 303. 21 . i. 30 (day). North of South Georgia. N 70 V. 750-500 m. : Dactylamblyops hodgsoni Holt and Tattersall. STATION LISTS 9 St. 305. 21/22. i. 30 (night). North of South Georgia. N 70 V. 750-500 m. : Dactylamblyops hodgsoni Holt and Tattersall. St. 322. 31. i. 30 (day). North-west of South Georgia. N 70 V. 750-500 m. : Dactylamblyops hodgsoni Holt and Tattersall. St. 323. 31. i. 30 (day). North-west of South Georgia. N 70 V. 750-500 m.: Dactylamblyops hodgsoni Holt and Tattersall. St. 326. 2. ii. 30 (night). West of South Georgia. N 70 V. 50-0 m.: Mysis australe sp.n. $ Types. 100-50 m. and 200-100 m. : Antarctomysis maxima Holt and Tattersall. St. 327. 2. ii. 30 (day). West of South Georgia. N 70 V. 50-0 m. : Mysis australe sp.n. 200-100 m. Antarctomysis maxima Holt and Tattersall. St. 331. 2. ii. 30 (day). West of South Georgia. N 70 V. 100-50 m.: Antarctomysis maxima Holt and Tattersall. St. 334. 4. ii. 30 (day). South of South Georgia. N 70 V. 750-500 m. : Dactylamblyops hodgsoni Holt and Tattersall. St- 337- 5- i'- 30 (day). South of South Georgia. N 70 V. 750-500 m.: Dactylamblyops hodgsoni Holt and Tattersall. St. 338. 5. ii. 30 (day). South of South Georgia. N 70 V. 225-100 m. : Antarctomysis maxima Holt and Tattersall. St- 339- 5. ii. 30 (day). South of South Georgia. N 70 V. 100-50 m. and 250-100 m.: Antarctomysis maxima Holt and Tattersall. St. 340. 5. i. 30 (night). South of South Georgia. N 70 V. 100-50 m. : Antarctomysis maxima Holt and Tattersall. St. 341. 5/6. ii. 30 (night). South-west of South Georgia. N 70 V. 50-0 m., 100-50 m., and 230-100 m. : Antarcto- mysis maxima Holt and Tattersall. St. 344. 7/8. ii. 30 (night). South-east of South Georgia. N 70 V. 1000-750 m. and 750-500 m.: Dactylamblyops hodgsoni Holt and Tattersall. St. 348. 8. ii. 30 (day). Off south-east of South Georgia. N 70 V. 90-50 m. : Antarctomysis maxima Holt and Tattersall. St. 349. 8. ii. 30 (night). South-east of South Georgia. N 70 V. 100-50 m. : Antarctomysis maxima Holt and Tattersall. St- 353- 9. ii. 30 (day). East of South Georgia. N 70 V. 1000-750 m.: Dactylamblyops hodgsoni Holt and Tattersall. St. 357. 10. ii. 30 (dusk to dark). North-east of South Georgia. N 70 V. 750-500 m. : Dactylamblyops hodgsoni Holt and Tattersall. St. 358. 11. ii. 30 (night). North-east of South Georgia. N 70 V. 1000-750 m. : Dactylamblyops hodgsoni Holt and Tattersall. St. 363. 26. ii. 30 (day). South Sandwich Is. DLH. 329-278 m.: Mysidetes posthon Holt and Tattersall. St. 366. 6. iii. 30 (day). 4 cables South of Cook Is., South Sandwich Is. DLH. 322-155 m. : Antarctomysis maxima Holt and Tattersall. St. 368. 8. iii. 30 (day). Douglas Strait, South Sandwich Is., 1 mile North of Twitcher Rock. DLH. 653 m.: Mysidetes posthon Holt and Tattersall. St- 371. 14. iii- 30 (day). 1 mile East of Montagu I., South Sandwich Is. N 4-T. 99-161 m.: Mysidetes crassa Hansen; Antarctomysis maxima Holt and Tattersall. St. 376. 11. iv. 30 (day). South of South Shetlands. N 70 V. 750-500 m. : Antarctomysis oh/ini Hansen. St. 391. 18. iv. 30 (day). Midway between South Georgia and Cape Horn. N 450 B. i30o-i20o(-o) m. (carapace only): Gnathophausia gigas W.-Suhm; Eucopia australis Dana. St- 395- x3- v- 3° (aav)- North-east of South Georgia, N 450 B. 1600-1500 m.: Eucopia australis Dana; Eucopia grimaldii Nouvel ; Boreomysis atlantica Nouvel. St. 405. 4. vi. 30 (day). West of Cape Town. TYFB. 1200-0 m. : Eucopia unguiculata (W.-Suhm); Boreomysis rostrata Illig. St. 406. 5. vi. 30 (day). 6 cables north-east of Roman Rocks, Simon's Bay, Cape Peninsula. BRN. 29 m. : Anchialina truncata (G. O. Sars); Mysidopsis camelina sp.n., ? Type; Leptomysis capensis Illig. St. 407. 12. vi. 30 (day). South-west of Cape Town. N 450 B. 950-800 m.: Gnathophausia ingens (Dohrn); Eucopia unguiculata (W.-Suhm); Boreomysis rostrata Illig; Meterythrops picta Holt and Tattersall. St. 413. 21. viii. 30 (day). West of Saldanha Bay, Natal. TYFB. 2200-1 6oo(-o) m.: Gnathophausia gigas W.-Suhm. 1 600-1000 m.: Gnathophausia gigas W.-Suhm; Eucopia australis Dana; Eucopia linguicauda sp.n. Type; Boreomysis rostrata Illig. St. 414. 28. viii. 30 (night). South of Cape Town. N 100 B. 1700-1000 m. : Eucopia sculpticauda Faxon. St. 421. 31. viii. 30 (day). South of Cape Town. N 100 B. 77-0 m. : Leptomysis capensis Illig. io DISCOVERY REPORTS St. 423. 3. ix. 30 (night). South of Port Elizabeth, South Africa. N100B. 56-0 m. : Anchialina truncata (G. O. Sars). St. 424. 4. xi. 30 (night). Off Port Elizabeth, South Africa. N 100 B. 59-0 m.: Lophogaster challengeri Fage; Anchialina truncata (G. O. Sars); Leptomysis capensis Illig. St. 436. 20. ix. 30 (day). Off Durban. BNR. 4i6(-o) m. : Amblyops durbani sp.n. Types. St. 437. 20. ix. 30 (night). East of Durban. N 100 B. 123-0 m. : Siriella thompsonii ' (M.-Ed.). St. 440. 21. ix. 30 (day). East of Durban. TYFB. io50-95o(-o) m.: Lophogaster rotundatus Illig; Eucopia unguicu- lata (W.-Suhm) ; Eucopia sculpticauda Faxon ; (dusk to dark) TYFB. 1000-0 m. : Gnathophausia ingens (Dohrn). St. 441. 22. ix. 30 (night). South-east of Durban. N 100 B. 180-0 m.: Siriella thompsonii (M.-Ed.). St. 443. 23. ix. 30 (night). South-west of Port Elizabeth. N 100 B. 49-0 m.: Gastrosaccus sanctus (v. Beneden); Anchialina truncata (G. O. Sars); Lophogaster challengeri Fage; Leoptomysis capensis Illig. St. 444. 24. ix. 39 (night). Off Cape Peninsula. N 100 B. 80-0 m.: Lophogaster challengeri 'Fage; Anchialina trun- cata (G. O. Sars); Leptomysis capensis Illig; Leptomysis megalops Zimmer. St. 448. 10. x. 30 (night). South-west of Cape Town. N 70 B. 161-0 m.: Siriella thompsonii (M.-Ed.). St. 461 D. 22. x. 30 (night). West-south-west of Bouvet Is. N 100 B. 490-385 m. : Euchaetomera zurstrasseni (Illig)- St. 517. 26. xi. 30 (night). East of South Georgia. N 100 B. 102-0 m. : Antarctomysis maxima Holt and Tattersall. St. 518. 27. xi. 30 (night). South Georgia. N 100 B. 90-0 m., Antarctomysis maxima Holt and Tattersall. 14 juv. 9-1 1 mm. St. 563. 1. i. 31 (day). Bellingshausen Sea. N 100 B. 450-180 m. : Euchaetomera zurstrasseni (Illig). St. 590. 14. i. 31 (day). West of Graham Land. TYFH. 1400-1150 m. : Eucopia australis Dana; Boreomysis brucei Tattersall; Dactylamblyops hodgsoni Holt and Tattersall; Euchaetomera zurstrasseni (Illig). St. 591. 14. i. 31 (day). West of Graham Land. N 100 B. 360-122 m. : Euchaetomera zurstrasseni (Illig). St. 592. 15. i. 31 (day). Bellingshausen Sea. N 100 B. 350-124 m.: Euchaetomera zurstrasseni (Illig). St. 594. 15. i. 31 (day). North-west of Graham Land. N 100 B. 435-165 m. : Euchaetomera zurstrasseni (Illig). St. 661. 2. iv. 31 (day). South-east of South Georgia. TYFV. 750-500 m. : Dactylamblyops hodgsoni Holt and Tattersall. 1500-1000 m. Boreomysis brucei Tattersall. 2000-1500 m. (night): Boreomysis brucei Tattersall; Dactylamblyops hodgsoni Holt and Tattersall. 3000-2000 m. (night): Eucopia australis Dana; Boreomysis brucei Tattersall ; Dactylamblyopsis hodgsoni Tattersall. St. 663. 5. iv. 31 (day). East-north-east of South Georgia. TYFV. 500-250 m.: Boreomysis rostrata Illig; Euchaeto- mera zurstrasseni (Illig). 1 500-1000 m. : Dactylamblyops hodgsoni Tattersall. 2000-1500 m.: Dactylamblyops hodgsoni Tattersall. St. 666. 17/18. iv. 31 (day). North-east of South Georgia. TYFV. 750-500 m. : Euchaetomera zurstrasseni (Illig). 1000-750 m.: Dactylamblyops hodgsoni Tattersall. St. 668. 19. iv. 31 (day). North-west of South Georgia. TYFV. 750-500 m. and 1500-0 m. : Euchaetomera zurstras- seni (Illig). St. 671. 22/23. 1V- 31 (n'ght)- South-west of Tristan da Cunha. TYFV. 1000-0 m. : Boreomysis rostrata Illig. 1 500-1 000 m. (night): Dactylamblyops hodgsoni Holt and Tattersall. St. 673. 25. iv. 31 (night). West of Tristan da Cunha. TYFB. 340-0 m. : Siriella thompsonii (M.-Ed.); Echinomysis chum Illig; Euchaetomera typica G. O. Sars; Euchaetomera tenuis G. O. Sars; Euchaetomera intermedia Nouvel. 500-250 m.: Euchaetomera zurstrasseni (Illig). 1000-750 m. : Caesaromysis hispida Ortmann. 1500-1000 m.: Boreomysis rostrata Illig. St. 674. 25. iv. 31 (night). West of Tristan da Cunha. TYFB. 280-0 m.: Euchaetomera typica G. O. Sars; Euchaeto- mera intermedia Nouvel; Arachnomysis megalops Zimmer. St. 675. 26. iv. 31 (day). West-north-west of Tristan da Cunha. TYFV. 1500-1000 m.: Eucopia australis Dana. St. 676. 26. iv. 31 (night). West-north-west of Tristan da Cunha. TYFB. 290-0 m. : Euchaetomera typica G. O. Sars. St. 677. 28. iv. 31 (night). Mid-Atlantic, North-west of Tristan da Cunha. TYFB. 420-0 m.: Siriella thompsonii (M.-Ed.). St. 679. 29. iv. 31 (night). South of Ilha da Trinidade. TYFB. 300-0 m. : Lophogaster spinosus Ortmann; Siriella thompsonii (M.-Ed.). 500-250 m. : Siriella thompsoni (M.-Ed.). 2000-1500 m. (day) : Eucopia grimaldii Nouvel. St. 680. 30. iv. 31 (night). South of Ilha da Trinidade. TYFB. 260-0 m. : Lophogaster spinosus Ortmann. St. 685. 3. v. 31 (night). East of San Salvador, Brazil. TYFB. 350-0 m. : Siriella thompsonii (M.-Ed.). St. 687. 5. v. 31 (day). South-east of Pernambuco. TYFV. 1500-1000 m. Eucopia australis Dana. St. 689. 6. v. 31 (night). East of Pernambuco. TYFB. 410-0 m. : Siriella thompsonii (M.-Ed.). STATION LISTS n St. 691. 8. v. 31 (night). Equator, south-west of Cape Verde Is. TYFB. 400-0 m. : Gnathophausia ingens (Dohrn). St. 692. 9. v. 31 (night). Mid- Atlantic, just north of equator. TYFB. 350-0 m.: Euchaetomera typica G. O. Sars; Caesaromysis hispida Ortmann; Arachnomysis megalops Zimmer. St. 693. 10. v. 31 (day). Mid- Atlantic near equator. TYFV. 250-0 m.: Boreomysis sibogae Hansen; Euchaetomera typica G. O. Sars. 750-500 m. : Eucopia unguiculata (W.-Suhm). 2000-1500 m. : Eucopia australis Dana. St. 694. 10. v. 31 (night). Mid-Atlantic, south-south-west of Cape Verde Is. TYFB. 210-0 m.: Siriella thompsonii (M.-Ed.); Euchaetomera typica G. O. Sars; Arachnomysis leuckartii Chun; Arachnomysis megalops Zimmer. St. 695. 11. v. 31 (night). Mid- Atlantic, south-south-west of Cape Verde Is. TYFB. 370-0 m.: Siriella thompsonii (M.-Ed.); Euchaetomera tenuis G. O. Sars; Euchaetomera glyphidophthalmica Illig; Caesaromysis hispida Ortmann. St. 696. 12. v. 31 (day). South-west of Cape Verde Is. TYFV. 1000-750 m.: Boreomysis illigi sp.n. ; Eucopia un- guiculata (W.-Suhm); Eucopia sculpticauda Faxon. St. 697. 12. v. 31 (night). Mid-Atlantic, south-west of Cape Verde Is. TYFB. 460-0 m.: Siriella thompsonii (M.-Ed.); Euchaetomera tenuis G. O. Sars; Caesaromysis hispida Ortmann; Arachnomysis megalops Zimmer. St. 698. 13. v. 31 (night). South-west of Cape Verde Is. TYFB. 470-0 m. : Siriella thompsonii (M.-Ed.); Euchaeto- mera typica G. O. Sars; Euchaetomera intermedia Nouvel. St. 699. 14. v. 31 (night). West of Cape Verde Is. TYFB. 370-0 m. : Siriella thompsonii (M.-Ed.); Euchaetomera typica G. O. Sars; Caesaromysis hispida Ortmann; Arachnomysis megalops Zimmer; TYFV. 250-0 m. (day): Arachnomysis leuckartii Chun; Caesaromysis hispida Ortmann. TYFV. 1000-750 m. (day): Eucopia australis Dana; Eucopia sculpticauda Faxon. St. 700. 18. 5. 3 1 (day). North-east of Cape Verde Is. TYFB. 2025-0 m. : Gnathophausia gracilis W.-Suhm ; Eucopia unguiculata (W.-Suhm); Eucopia australis Dana; Eucopia sculpticauda Faxon; Eucopia grimaldii Nouvel; Siriella thompsonii (M.-Ed.); Meterythrops picta Holt and Tattersall; Katerythrops oceanae Holt and Tattersall; Euchaetomera intermedia Nouvel. St. 701. 16. x. 31 (night). Off Cape Verde Is. TYFB. 242-0 m. Euchaetomera typica G. O. Sars; Euchaetomera glyphidophthalmica Illig. St. 702. 17. x. 31 (night). West of Sierra Leone. TYFB. 236-0 m. : Euchaetomera tenuis G. O. Sars. St. 703. 18. x. 31 (night). South-south-west of Cape Verde Is. TYFB. 358-0 m. : Siriella thompsonii (M.-Ed.). St. 704. 19. x. 31 (night). South of Cape Verde Is. TYFB. 231-0 m.: Siriella thompsonii (M.-Ed.); Anchialina typica (Kroyer); Euchaetomera intermedia Nouvel; Arachnomysis megalops Zimmer. St. 705. 20. x. 31 (night). North-east of Pernambuco. TYFB. 150-0 m. : Siriella thompsonii (M.-Ed.). St. 706. 21.x. 31 (night). North-east of Pernambuco. TYFB. 354-0 m.: Siriella thompsonii (M.-Ed.); Caesaromysis hispida Ortmann ; Arachnomysis megalops Zimmer. St. 709. 24. x. 31 (night). Off Abrolhos Is. TYFB. 216-0 m.: Siriella thompsonii (M.-Ed.). St. 713. 29. x. 31 (night). East of Porto Alegre, Brazil. TYFB. 200-0 m.: Siriella thompsonii (M.-Ed.). St. 714. 30. x. 31 (night). East of Monte Video. TYFB. 246-0 m.: Katerythrops oceanae Holt and Tattersall; Euchaetomera intermedia Nouvel. St. 717. 2. xi. 31 (night). North-north-east of Falkland Is. TYFB. 212-0 m.: Euchaetomera intermedia Nouvel. St. 844. 8. iv. 32 (night). South of Cape Town. N 100 B. 155-0 m.: Lophogaster challengeri Fage; Anchialina truncata (G. O. Sars); Longithorax capensis Illig; Leptomysis megalops Zimmer. St. 942. 31. viii. 32 (night). East of Cook Strait, New Zealand. N 100 B. 350-110 m.: Boreomysis rostrata Illig (doubtfully). St. 946. 3. ix. 32 (night). South of Chatham I. N 100 B. 270-120 m. : Euchaetomera zurstrasseni (Illig). St. 971. 25. ix. 32 (night). North of Bellingshausen Sea. N 100 B. 340-120 m. : Euchaetomera zurstrasseni (Illig)- St. 980. 15. x. 32 (night). East of Magellan Strait. N 100 B. 104-0 m. : Mysidopsis acuta Hansen. St. 1298. 2. iii. 34 (day). Ice Edge, Bellingshausen Sea. N 450 H. iooo(-o) m.: Gnathophausia gigas W.-Suhm; Eucopia australis Dana. St. 1371. 19. v. 34 (night). South-east of Port Elizabeth. N 70 B. 146-0 m.: Siriella thompsonii (M.-Ed.). St. 1372. 20. v. 34 (night). East of East London. N 70 B. 102-0 m. : Siriella thompsonii (M.-Ed.). St. 1374. 24. v. 34 (night). East of St Johns, Natal. TYFB. 230-0 m. : Longithorax capensis Zimmer. St- 1377- 4- viii- 34 (night). South-west of Cape Town. N 100 B. 100-0 m.: Euchaetomera typica G. O. Sars. St. 1517- St. 1539- Illig. St. 1555- St. 1558- St. 1561. DISCOVERY REPORTS 14. ii. 35 (night). Ice-edge east of Weddell Sea. N 100 B. 420-230 m. : Euchaetomera zurstrasseni Illig. 25. ii. 35 (night). Ice-edge off Enderby Land. N 100 B. 350-230 m.: Euchaetomera zurstrasseni 29. iii. 35 (night). South of South Africa. TYFB. 1000-0 m.: Katerythrops oceanae Holt and Tattersall. 1. iv. 35 (night). West of Prince Edward Is. TYFB. 1300-0 m. : Euchaetomera zurstrasseni Illig. 4. iv. 35 (night). West of Prince Edward Is. TYFB. 1250-0 m.: Dactylamblyops hodgsoni Holt and Tattersall. St. 1566. 9. iv. 35 (night). North of Prince Edward Is. TYFB. 1350-0 m. : Boreomysis rostrata Illig. St. 1567. 10. iv. 35 (night). North of Prince Edward Is. TYFB. 1350-0 m.: Gnathophausia ingens (Dohrn); Siriella thompsonii (M.-Ed.). St. 1568. 11. iv. 35 (night). South-east of Durban. TYFB. 1400-0 m.: Boreomysis rostrata Illig; Euchaetomera tenuis G. O. Sars; Euchaetomera oculata Hansen; Gibberythrops acanthura (Illig). St. 1569. 12. iv. 35 (night). South-east of Durban. TYFB. 1200-500 m. : Meterythrops picta Holt and Tattersall. St. 1571. 21. iv. 35 (night). South-west of Madagascar. TYFB. 500-0 m. : Siriella thompsonii {M.-Ed.). 1400- 1000 m. : Gnathophausia ingens (Dohrn); Euchaetomera intermedia Nouvel. St. 1573. 22. iv. 35 (night). Mozambique Channel. TYFB. 800-0 m.: Gnathophausia ingens (Dohrn). St. 1574. 23. iv. 35 (night). Mozambique Channel. TYFB. 1 100-450 m. : Eucopia unguiculata (W.-Suhm) ; Eucopia australis Dana; Eucopia sculpticauda Faxon. St. 1575. 24. iv. 35 (night). Mozambique Channel. TYFB. 400-0 m. and 800-550 m. : Gnathophausia ingens (Dohrn). N 70 B. 800-0 m. (night); Katerythrops oceanae Holt and Tattersall. St. 1576. 25. iv. 35 (night). Mozambique Channel. TYFB. 400-0 m. : Gnathophausia ingens (Dohrn). 1 100-400 m. : Eucopia australis Dana; Eucopia sculpticauda Faxon. St. 1578. 26. iv. 35 (night). North of Mozambique Channel. TYFB. 500-0 m.: Gnathophausia ingens (Dohrn); Siriella aequiremis Hansen; Euchaetomera typica G. O. Sars. St. 1580. 27. iv. 35 (night). South-east of Zanzibar. TYFB. 450-0 m.: Gnathophausia ingens (Dohrn). N 70 B. 1300-0 m.: Eucopia sculpticauda Faxon. TYFB. 1300-750 m. : Eucopia unguiculata (W.-Suhm). St. 1581. 28. iv. 35 (night). East of Zanzibar. TYFB. 600-0 m. : Euchaetomera tenuis G. O. Sars. St. 1582. 29. iv. 35 (night). East of Zanzibar. N 450 H. I900-i85o(-o) m.: Gnathophausia ingens (Dohrn); Gnathophausia zoea W.-Suhm; Eucopia unguiculata (W.-Suhm); Eucopia australis Dana; Eucopia sculpticauda Faxon ; Eucopia grimaldii Nouvel. St. 1585. 1. v. 35 (night). East of Juba, Somaliland. TYFB. 500-0 m.: Lophogaster schmidti Fage; Siriella gracilis Dana; Siriella aequiremis Hansen; Caesaromysis hispida Ortmann. 1400-700 m.: Eucopia unguiculata (W.-Suhm); Eucopia sculpticauda Faxon; Eucopia grimaldii Nouvel; Boreomysis tattersalli sp.n. St. 1586. 2. v. 35 (night). East of Somaliland. TYFB. 550-0 m. : Gnathophausia ingens (Dohrn); Siriella aequiremis Hansen; Petalophthalmus oculatus Illig; Gibberythrops acanthura Illig; Longithorax capensis Zimmer; Euchaeto- mera tenuis G. O. Sars. 1650-950 m.: Eucopia unguiculata (W.-Suhm); Eucopia sculpticauda Faxon; Eucopia grimaldii Nouvel. St. 1587. 3. v. 35 (night). South of Cape Guardafui. TYFB. 450-0 m. : Lophogaster schmidti Fage; Echinomysis chuni Illig. 1250-800 m.: Lophogaster schmidti Fage; Eucopia unguiculata (W.-Suhm); Eucopia sculpticauda Faxon; Boreomysis tattersalli sp.n. Types; Gibberythrops acanthura (Illig). St. 1590. 13. x. 35 (night). South of Canary Isles. TYFB. 400-320 m. : Gnathophausia ingens (Dohrn). St. 1596. 21. x. 35 (night). Gulf of Guinea. TYFB. 450-310 m. : Euchaetomera typica G. O. Sars. St. 1602. 27. x. 35 (night). East of St Helena. TYFB. 470-300 m.: Boreomysis rostrata Illig; Boreomysis illigi sp.n. 175-0 m. : Siriella thompsonii (M.-Ed.); Euchaetomera typica G. O. Sars. St. 1604. 29. x. 35 (night). South-east of St Helena. TYFB. 620-500 m.: Boreomysis plebeja Hansen; Boreomysis rostrata Illig; Meterythrops picta Holt and Tattersall. St. 1606. 31. x. 35 (night). West of Angra Pequena, South-west Africa. TYFB. 600-500 m.: Heteroerythrops purpura gen. et sp.nov. 9 Type; Boreomysis rostrata Illig; Boreomysis plebeja Hansen; Meterythrops picta Holt and Tattersall. St. 1633. 29. xi. 35 (day). South-east of Heard Is. N 70 B. 1100-875 m-: Dactylamblyops hodgsoni Holt and Tattersall. St. 1644. 16. i. 36 (day). Bay of Whales. BNR. 626 m.: Pseudomma belgicae (Hansen in MS.), Holt and Tattersall; Antarctomysis maxima Holt and Tattersall. STATION LISTS 13 St. 1652. 23. i. 36 (day). Bay of Whales, Ross Sea. DLH. 567 m. : Amblyops antarctica sp.n.; Mysidetes post/ion Holt and Tattersall; Antarctomysis maxima Holt and Tattersall. St. 1660. 27. i. 36 (day). Bay of Whales. N 7-T. 351 m.: Mysidetes post/ion Holt and Tattersall; Antarctomysis maxima Holt and Tattersall. St. 1702. 17. iii. 36 (day). Ice Edge off Wilkes Land. TYFB. 2000-1250 m. : Boreomysis brucei W. M. Tattersall; Dactylamblyops hodgsoni Holt and Tattersall. St. 1715. 23. iii. 36 (night). Ice Edge off Budd's High Land. TYFB. 1400-1100 m. : Dactylamblyops hodgsoni Holt and Tattersall. St. 1739. 17. iv. 36 (day). West of Perth, Western Australia. TYFB. 300o-200o(-o) m. : Katerythrops oceanae Holt and Tattersall. St. 1741. 18. iv. 36 (day). West of Perth, Western Australia. N 450 B. 900-0 m.: Gnathophausia ingens (Dohrn). St. 1747. 23. iv. 36 (day). Indian Ocean, North of Amsterdam Is. TYFB. 400-0 m.: Euchaetomera typica G. O. Sars. St. 1753. 27. iv. 36 (day). North-west of New Amsterdam, South Indian Ocean. TYFB. 2900-1400 m. : Boreomysis rostrata Illig; Katerythrops oceanae Holt and Tattersall. St. 1755. 29. iv. 36 (day). South-south-east of Mauritius. N 450 B. 1700-0 m. : Gnathophausia gigas W .-Suhm. St. 1761. 3. v. 36 (day). South of Madagascar. TYF 70 B. 1800-650 m. : Gnathophausia ingens (Dohrn); Metery- throps picta Holt and Tattersall. St. 1763. 5. v. 36 (day). South-east of Durban. N 450 B. 2000-0 m. : Gnathophausia ingens (Dohrn). St. 1764. 6. v. 36 (night). South-east of Durban. N 450 B. 1 000-0 m. : Gnathophausia ingens (Dohrn). St. 1765. 7. v. 36 (day). East of East London, South Africa. TYF 70 B. 1350-800 m. : Eucopia sculpticauda Faxon. St. 1770. 21. v. 36 (night). West of Cape Town. N 100 B. 340-210 m. : Gnathophausia ingens (Dohrn). St. 1775. 27. v. 36 (night). South-east of Gough I. N 70 V. 1500-1000 m.: Gnathophausia gigas W.-Suhm. St. 1798. 12. vi. 36 (night). North-east of Bouvet I. N 70 V. 1000-750 m. : Gnathophausia gigas W.-Suhm. St. 1802. 16. ix. 36 (day). Off Cape Town. N 70 V. 1000-750 m.: Boreomysis rostrata Illig. St. 1838. 12. x. 36 (day). West-north-west of South Sandwich Is. TYF 70 V. 750-250 m. : Dactylamblyops hodgsoni Holt and Tattersall; Euchaetomera zurstrasseni (Illig). St. 1855. 4. xi. 36 (day). Off South Georgia. TYF 70 B. 1050-500 m. : Dactylamblyops hodgsoni Holt and Tattersall. St. 1866. 9. xi. 36 (night). Scotia Sea. N 100 B. 380-200 m. : Antarctomysis maxima Holt and Tattersall (Hansen in MS.). St. 1869. 1 1. xi. 36 (day). Scotia Sea. TYFB. 1550-1000 m. : Eucopia grimaldii Nouvel; Boreomysis brucei Tattersall. St. 1871. 12. xi. 36 (day). East of South Shetlands. TYFB. 1450-1000 m. : Boreomysis brucei Tattersall; Dactyl- amblyops hodgsoni Holt and Tattersall. St. 1872. 12. xi. 36 (day). Scotia Sea. N 100 H. 247 m. : Mysidetes posthon Holt and Tattersall; Antarctomysis maxima Holt and Tattersall. St. 1873. 13. xi. 36 (day). South of Falkland Is. DRR. 210-180 m. : Antarctomysis maxima Holt and Tattersall. St. 1915. 2. xii. 36 (day). Scotia Sea. TYFB. 550-350 m. Euchaetomera zurstrasseni (Illig). St. 1917. 3. xii. 36 (day). Off South Georgia. TYFB. 1400-1000 m. : Dactylamblyops hodgsoni Holt and Tattersall. St. 1919. 4. xii. 36 (day). Off South Georgia. TYFB. 1800-1300 m.: Eucopia australis Dana; Dactylamblyops hodgsoni Holt and Tattersall. St. 1944. 2. i. 37 (day). North of South Orkneys. TYFB. 1 500-1 200 m. : Dactylamblyops hodgsoni Holt and Tattersall. St. 1946. 3. i. 37 (day). West of South Orkneys. TYFB. 1700-1300 m.: Dactylamblyops hodgsoni Holt and Tattersall. St. 1952. 11. i. 37 (day). South Shetlands. DLH. 367-383 m. : Antarctomysis maxima Holt and Tattersall (Hansen in MS.). St. 1955. 29. i. 37 (day). South Shetlands. DLH. 440-410 m.: Mysidetes posthon Holt and Tattersall; Antarcto- mysis maxima Holt and Tattersall. St- 1957- 3- ii- 37 (day). Off South side of Clarence I., South Shetlands. DLH. 785-810 m. : Pseudomma sarsi (W.-Suhm); Pseudomma ant arcticum Zimmer; Amblyops antarctica sp.n. 9 Type; Mysidetes posthon Holt and Tattersall. St. 1966. 16. ii. 37 (day). North of South Orkneys. TYFB. 1800-1500 m.: Boreomysis brucei Tattersall ; Dactyl- amblyops hodgsoni Holt and Tattersall. 14 DISCOVERY REPORTS St. 1970. 18. ii. 37 (day). Scotia Sea. TYFB. 1800-1500 m.: Eucopia unguiculata (W.-Suhm); Eucopia australis Dana; Dactylamblyops hodgsoni Holt and Tattersall. St. 1972. 28. ii. 37 (day). Scotia Sea. TYFB. 2100-1400 m.: Dactylamblyops hodgsoni Holt and Tattersall. St. 1974. 1. iii. 37 (day). Scotia Sea. TYFB. 1600-1000 m. : Eucopia unguiculata (W.-Suhm). St. 1989. 10. iii. 37 (day). East of South Georgia. TYFB. 1500-1200 m. : Boreomysis plebeja Hansen; Dactyl- amblyops hodgsoni Holt and Tattersall. St. 1991. 11. hi. 37 (day). South-east of South Georgia. TYFB. 1500-1000 m.: Gnathophausia gigas W.-Suhm; Boreomysis brucei Tattersall; Dactylamblyops hodgsoni Holt and Tattersall. St. 1993. 12. iii. 37 (day). South-west of South Sandwich Is. TYFB. 950-650 m. : Dactylamblyops hodgsoni Holt and Tattersall. St. 1995. 13. iii. 37 (day). South-south-east of South Sandwich Is. TYFB. 1800-1300 m.: Boreomysis brucei Tattersall. St. 1999. 15. iii. 37 (day). South-east of South Sandwich Is. N 100 B. 1000-500 m. : Dactylamblyops hodgsoni Holt and Tattersall. St. 2006. 19. iii. 37 (day). East of South Sandwich Is. TYFB. 1750-1400 m.: Dactylamblyops hodgsoni Holt and Tattersall. St. 2018. 26. iii. 37 (night). West of Bouvet Isle. N 70 V. 1000-750 m. : Dactylamblyops hodgsoni Holt and Tattersall. St. 2022. 28. iii. 37 (night). North-west of Bouvet Is. N 100 B. 700-400 m. : Gnathophausia gigas W.-Suhm. St. 2033. 6. iv. 37 (day). Off Cape Town. TYFB. 1350-1250 m.: Boreomysis bispinosa sp.n. ? Type. St. 2034. 6. iv. 37 (night). West of Cape Town. N 100 B. 162-0 m. : Boreomysis illigi sp.n. St. 2035. 7. iv. 37 (day). Off Cape Town. TYFB. 950-750 m. : Eucopia unguiculata (W.-Suhm); Boreomysis rostrata Illig. St. 2038. 19. iv. 37 (day). West of Cape Town. TYFB. 1200-850 m. : Boreomysis rostrata Illig. St. 2042. 22. iv. 37 (day). West of Saldanha Bay, South Africa. N 100 H. 0-5 m.: Siriella thompsonii (M.-Ed.). St. 2044. 23. iv. 37 (day). Due west of Orange River estuary. N 100 H. 0-5 m. : Siriella thompsonii (M.-Ed.). St. 2053. 27. iv. 37 (day). East-south-east of St Helena. TYFB. 900-550 m. : Eucopia australis Dana. St. 2055. 28. iv. 37 (day). East of St Helena. TYFB. 2000-1400 m.: Eucopia sculpticauda Faxon; Boreomysis acuminata sp.n. St. 2057. 29. iv. 37 (day). North-east of St Helena. N 450 B. 1450-700 m.: Gnathophausia gracilis W.-Suhm; Eucopia australis Dana; Eucopia sculpticauda Faxon; Eucopia grimaldii Nouvel; Boreomysis bispinosa sp.n. cS Type. St. 2059. 30. iv. 37 (day). North-north-east of St Helena. N 450 B. 1400-0 m. : Gnathophausia gracilis W.-Suhm. 1900-1400 m. : Eucopia australis Dana; Eucopia sculpticauda Faxon; Eucopia grimaldii Nouvel. St. 2061. 1. v. 37 (day). East-north-east of Ascension I. N 450 B. 1900-1500 m.: Eucopia australis Dana; Eucopia sculpticauda Faxon. St. 2063. 2. v. 37 (day). North-east of Ascension I. N 450 B. 600-0 m. : Eucopia australis Dana; Eucopia sculpti- cauda Faxon ; Boreomysis microps G. O. Sars. 1 1 50-600 m. : Eucopia australis Dana ; Eucopia sculpticauda Faxon ; Boreomysis microps G. O. Sars. St. 2064. 3. v. 37 (day). North-north-east of Ascension I. N 450 B. 1600-1050 m.: Gnathophausia zoea W.-Suhm; Eucopia sculpticauda Faxon; Eucopia australis Dana; Eucopia grimaldii Nouvel; Boreomysis microps G. O. Sars; Boreomysis acuminata sp.n. St. 2065. 4. v. 37 (day). North of Ascension I. N 450 B. 1600-1400 m. : Eucopia unguiculata (W.-Suhm); Eucopia australis Dana; Eucopia sculpticauda Faxon; Eucopia grimaldii Nouvel; Boreomysis microps G. O. Sars; Boreomysis acuminata sp.n. St. 2066. 5. v. 37 (day). South-west of Monrovia. N 450 B. 1950-1550 m. : Eucopia unguiculata (W.-Suhm); Eucopia australis Dana; Eucopia sculpticauda Faxon; Boreomysis acuminata sp.n., Types. 1550-0 m. : Eucopia sculpticauda Faxon. St. 2550. 23. i. 39 (night). 670 27-8' S., 060 35-3° E., off Pack Ice. TYFB. 430-230 m.: Euchaetomera zurstrasseni (Ulig). St. 2682. 8. vi. 50 (night). South-east of Aden. N 70 V. 750-500 m. : Eucopia unguiculata (W.-Suhm). St. 2685. 22. vi. 50 (night). 070 03' S., 90° 00' E. N 70 V. 250-100 m. : Euchaetomera typica G. O. Sars. STATION LISTS IS R.R.S. 'WILLIAM SCORESBY' St. WS 22. 30. xi. 26 (day). North of South Georgia. N 70 V. 1000-750 m.: Dactylamblyops hodgsoni Holt and Tattersall. St. WS 25. 17. xii. 26 (night). Undine Harbour (North), South Georgia. BTS. 18-27 m- : Antarctomysis maxima Holt and Tattersall. St. WS 26. 18. xii. 26 (dusk to dark). North of Bird Is., South Georgia. N 70 V. 1000-750 m. : Boreomysis sibogae Hansen. St. WS 27. 19. xii. 26 (day). Off South Georgia. N 100 H. 107 m. : Antarctomysis maxima Holt and Tattersall. St. WS 28. 19. xii. 26 (day). Off South Georgia. N 100 H. 80 m. and 145-100 m.: Antarctomysis maxima Holt and Tattersall. St. WS 29. 19. xii. 26 (day). Off South Georgia. N 70 V. 50-0 m. : Antarctomysis maxima Holt and Tattersall; 600-500 m. : Boreomysis rostrata var. (with large eyes) Illig; Boreomysis sibogae Hansen. St. WS 30. 19/20. xii. 26 (night). Off South Georgia. N 70 V. 100-50 m.: Antarctomysis maxima Holt and Tattersall. 250-100 m. : Euchaetomera zurstrasseni (Illig); A. maxima Holt and Tattersall. 750-500 m.: Dactylamblyops hodgsoni Holt and Tattersall. St. WS31. 20. xii. 26 (day). South-east of South Georgia. N 100 H. 53 m. : Antarctomysis maxima Holt and Tattersall. St. WS 32. 21. xii. 26 (day). Mouth of Drygalski Fiord, South Georgia. BTS. 225 m. : Antarctomysis maxima Holt and Tattersall ; Antarctomysis ohlini Hansen. St. WS 33. 21. xii. 26 (day). South of Drygalski Fiord, South Georgia. N 100 H. 130 m. (bottom): Antarctomysis maxima Holt and Tattersall. St. WS35. 21/22. xii. 26 (night). South of South Georgia. N100H. 51 m.: Antarctomysis maxima Holt and Tattersall. St. WS 37. 22. xii. 26 (day). Off South Georgia. N 70 V. 300-250 m. : Antarctomysis maxima Holt and Tattersall. St. WS 38. 22/23. xn- 2f) (n'gnt)- East of South Georgia. N 70 V. 1000-750 m.: Dactylamblyops hodgsoni Holt and Tattersall. St. WS 40. 7. i. 27 (day). Off South Georgia. N 70 V. 100-50 m. and 175-100 m. : Antarctomysis maxima Holt and Tattersall. St. WS 41. 7. i. 27 (day). Off South Georgia. N 100 H. 146 m. : Antarctomysis maxima Holt and Tattersall. St. WS 42. 7. i. 27 (dusk to dark). Off south of South Georgia. N 70 V. 170-100 m. (night). N 100 H. 99 m. and 198 m.: Antarctomysis maxima Holt and Tattersall. St. WS 43. 7/8. i. 27 (night). South of South Georgia. N 70 V. 50-0 m., N 100 H. 0-5 m., 70 m. and 141 m. : Antarctomysis maxima Holt and Tattersall. St. WS 44. 8. i. 27 (day). South of South Georgia. N 70 V. 750-500 m.: Dactylamblyops hodgsoni Holt and Tattersall; Antarctomysis maxima Holt and Tattersall (no depth on label). St. WS 45. 8. i. 27 (day). Off South Georgia. N 70 V. 100-50 m. and 175-100 m. ; N 100 H. 51m. and 102 m. : Antarctomysis maxima (Hansen MS.) Holt and Tattersall. St. WS 46. 8. i. 27 (night). Off South Georgia. N 70 V. 50-0 m., 171-50 m., 100-50 m.; N 100 H. 73 m. and 146 m.: Antarctomysis maxima (Hansen MS.) Holt and Tattersall. St. WS 47. 9. i. 27 (night). Off South Georgia. N 100 H. 0-5 m., 63 m. and 126 m. ; N 70 V. 50-0 m., 100-50 m. and 150-100 m.: Antarctomysis maxima Holt and Tattersall. St. WS 48. 9. i. 27 (day). West of Cape Nunez, South Georgia. N 100 H. 96 m.; 192 m.; N 70 V. 50-0 m. ; 224- 100 m.: Antarctomysis maxima Holt and Tattersall (Hansen MS.). St. WS 49. 9. i. 27 (day). Off South Georgia. N 100 H. 69 m.; 137 m.; N 70 V. 100-50 m.; 225-100 m.: Antarcto- mysis maxima Holt and Tattersall. St. WS 50. 9. i. 27 (day). Off South Georgia. N 100 H. 71 m.; 142 m.; N 70 V. 50-0 m.; 225-100 m. : Antarcto- mysis maxima Holt and Tattersall. St. WS51. 9. i. 27 (day). Off South Georgia. N 100 H. 64 m.; 128 m.; N 70 H. 119 m.; N 70 V. 100-50 m.; 210-100 m. : Antarctomysis maxima Holt and Tattersall. St. WS 52. 10. i. 27 (day). North-west of South Georgia. N 100 H. 100 m. ; N 70 V. 180-100 m. : Antarctomysis maxima Holt and Tattersall. St. WS 62. 19. i. 27 (day). Wilson Harbour, South Georgia. BTS. 26-83 m.: Antarctomysis maxima Holt and Tattersall. 16 DISCOVERY REPORTS St. WS 89. 7. iv. 27 (day). 9 miles north 210 E. of Arenas Point Light, Tierra del Fuego. N7-T. 23-21 m.: Neo- mysis patagona Zimmer; Arthromysis magellanica (Cunningham). St. WS no. 26. v. 27 (dusk to dark). Off South Georgia. N 70 V. 980-750 m. : Boreotnysis rostrata Illig. St. WS 133. 14/15. vi. 27 (night). Midway between Gough Is. and Cape Town. N 70 H. 0-5 m.: Siriella thomp- sonii (M .-Ed.). St. WS 144. 19. ii. 28 (day). North-west of South Georgia. N 70 V. 270-100 m.: Dactylamblyops hodgsoni Holt and Tattersall; Antarctomysis maxima Holt and Tattersall. St. WS 173. 6/7. iii. 28 (night). East of South Georgia. N 70 V. 500-250 m. : Euchaetomera zurstrasseni (Illig). St. WS 177. 7. iii. 28 (day). South Georgia. N 100 B. 97-0 m. ; Antarctomysis maxima Holt and Tattersall. St. WS 210. 29. v. 28 (day). North of Falkland Is. NCS-T. 161 m. : Mysidetes patagonica sp.n. St. WS211. 29. v. 28 (day). North of Falkland Is. NCS-T. 161-174 m. : Mysidopsis acuta Hansen. St. WS 212. 30. v. 28 (day). North of Falkland Is. N 4-T. 242-249 m.: Hansenomysis falklandica sp.n.; Mysidetes brachylepis W. M. Tattersall; Mysidetes macrops sp.n. St. WS 213. 30. v. 28 (day). North of Falkland Is. NCS-T. 249-239 m.: Hansenomysis falklandica sp.n., Types; Pseudomma sarsi (W.-Suhm); Mysidetes macrops sp.n.; Mysidetes crassa Hansen. St.WS2i4- 31. v. 28 (day). North of Falkland Is. NCS-T. 208-219 m.: Hansenomysis falklandica sp.n.; Mysidetes patagonica sp.n. St. WS 215. 31. v. 28 (dusk to night). North of Falkland Is. NCS-T. 219-146 m.: Pseudomma calmani sp.n.; Mysidetes patagonica sp.n. St. WS 219. 3. vi. 28 (day). North of Falkland Is. NCS-T. 116-114 m.: Pseudomma calmani sp.n.; Mysidetes posthon Holt and Tattersall; Mysidetes microps sp.n. (doubtfully); Mysidopsis acuta Hansen. St. WS 220. 3. vi. 28 (dusk to dark). North of Falkland Is. NCS-T. 108-104 m. : Mysidopsis acuta Hansen. St. WS 222. 8. vi. 28 (day). North-west of Falkland Is. NCS-T. 100-106 m. : Mysidopsis acuta Hansen. St. WS 226. 10. vi. 28 (day). North-west of Falkland Is. NCS-T. 144-152 m. : Pseudomma calmani sp.n.; Mysidetes crassa Hansen; Mysidopsis acuta Hansen. St. WS 227. 12. vi. 28 (night to dawn). East of Falkland Is. NCS-T. 320-298 m. : Hansenomysis falklandica sp.n.; Mysidetes macrops sp.n. St. WS 229. 1. vii. 28 (day). North-east of Falkland Is. NCS-T. 210-271 m. : Hansenomysis falklandica sp.n.; Pseudomma calmani sp.n.; Mysidetes posthon Holt and Tattersall; Mysidetes macrops sp.n. St. WS233. 5. vii. 28 (day). North of Falkland Is. NCS-T. 185-175 m.: Hansenomysis falklandica sp.n.; Mysidetes patagonica sp.n.; Mysidetes macrops sp.n.; Mysidopsis acuta Hansen. St. WS 234. 5. vii. 28 (night). North of Falkland Is. NCS-T. 195-207 m. : Hansenomysis falklandica sp.n.; Pseudomma sarsi (W.-Suhm); Mysidetes patagonica sp.n.; Mysidetes macrops sp.n. St. WS 235. 6. vii. 28 (day). North of Falkland Is. NCS-T. 155-155 m. : Pseudomma calmani ' sp.n. St. WS 236. 6. vii. 28 (dusk to dark). North of Falkland Is. NCS-T. 272-300 m. : Hansenomysis falklandica sp.n. ; Mysidetes patagonica sp.n.; Mysidetes macrops sp.n. St. WS 237. 7. vii. 28 (day). North of Falkland Is. NCS-T. 150-256 m. : Antarctomysis maxima Holt and Tattersall. St. WS 239. 15. vii. 28 (night). West of Falkland Is. NCS-T. 196-193 m. : Hansenomysis falklandica sp.n.; Mysidetes posthon Holt and Tattersall; Mysidetes patagonica sp.n. St. WS 243. 17. vii. 28 (dusk to dark). West of Falkland Is. N 4-T. 144-141 m.: Mysidetes intermedia sp.n.; Mysidopsis acuta Hansen. St. WS. 244. 18. vii. 28 (day). West of Falkland Is. N 4-T. 253-247 m. Hansenomysis falklandica sp.n.; Mysidetes patagonica sp.n., Types; Mysidetes macrops sp.n. St. WS 245. 18. vii. 28 (night). South-west of Falkland Is. N 4-T. 304-290 m.: Hansenomysis falklandica sp.n.; Mysidetes macrops sp.n. St. WS 330. 27. xii. 28 (day). North-east of South Georgia. N 70 V. 900-760 m. : Boreomysis rostrata var. (with very large eyes) Illig. St. WS 385. 16. ii. 29 (night). Bransfield Strait, South Shetland Is. N 70 V. 1000-750 m. : Boreomysis brucei W. M. Tattersall; Dactylamblyops hodgsoni Holt and Tattersall. St. WS 552. 3. ii. 31 (day). Pack Ice, East of Weddell Sea. N 70 V. 250-200 m.: Euchaetomera zurstrasseni (Ulig). St. WS 582. 30. iv. 31 (day). Magellan Strait. BTS. 1 10 m. : Boreomysis rostrata Illig. STATION LISTS i7 St. WS 583. 2. v. 31 (day). Magellan Strait. BTS. 14-78 m.: Mysidetes patagonica sp.n. St. WS748. 16. ix. 31 (night). Magellan Strait. NR. 30o(-o) m.: Hansenomysis falklandica sp.n.; Boreomysis rostrata Illig; Pseudomma magellanensis sp.n., Types; Amblyops sp., near kempi (Holt and Tattersall); Amblyopsoides obtusa sp.n.; Mysidetes patagonica sp.n.; Mysidetes intermedia sp.n.; Mysidetes anomala sp.n. Types. St. WS749. 18. ix. 31 (day). Magellan Strait. NR. 4o(-o) m: Hansenomysis falklandica sp.n.; Boreomysis rostrata Illig; Mysidetes anomala sp.n.; Neomysis patagona Zimmer; Arthromysis magellanica (Cunningham). St. WS 758. 1 2. x. 3 1 (night). North of Falkland Is. NR. 94-0 m. : Pseudomma calmani sp.n. ; Mysidetes intermedia sp.n., Types; Mysidopsis acuta Hansen. ii2(-o) m.: Mysidetes patagonica sp.n. St. WS767. 19. x. 31 (night). North of Falkland Is. NR. 98(-o)m.: Mysidopsis acuta Hansen; Pseudomma calmani sp.n. St. WS772. 30. x. 31 (day). North of Falkland Is. NCS-T. 309-163 m.: Pseudomma calmani sp.n. (Types); Mysidetes macrops sp.n. (Types). St. WS 773. 3 1 . x. 3 1 (day). North of Falkland Is. NCS-T. 291-298 m. : Hansenomysis falklandica sp.n. ; Mysidetes crassa Hansen. St.WS775. 2. xi. 31 (day). Patagonian Shelf, north-north-west of Falkland Is. NCS-T. 115-nom.: Pseudomma calmani sp.n. St. WS 781. 6. xi. 31 (day). Patagonian Shelf, north of Falkland Is. NCS-T. 148 m.: Mysidopsis acuta Hansen. St. WS782. 4. xii. 31 (day). North of Falkland Is. N 4-T. 141-146 m.: Mysidopsis acuta Hansen. St. WS 784. 5. xii. 31 (day). North of Falkland Is. NCS-T. 170-164 m.: Mysidetes intermedia sp.n. (doubtful). St. WS786. 7. xii. 31 (day). Patagonian Shelf, north-west of Falkland Is. N 4-T. 1 34-1 19 m.: Mysidopsis acuta Hansen. St. WS 787. 7. xii. 31 (day). Patagonian Shelf, north-west of Falkland Is. NCS-T. 106-110 m.: Mysidopsis acuta Hansen. St. WS798. 20. xii. 31 (day). Patagonian Shelf, north-west of Falkland Is. NCS-T. 49-66 m. : Mysidopsis acuta Hansen; Neomysis monticellii Colosi. St. WS801. 22. xii. 31 (day). Patagonian Shelf, north of Falkland Is. NCS.-T. 165 m.: Pseudomma calmani sp.n.; Mysidetes intermedia sp.n. ; Mysidopsis acuta Hansen. St. WS 802. 5. i. 32 (day). Patagonian Shelf, north of Falkland Is. Haul A. NCS-T. 128-132 m.: Mysidopsis acuta Hansen; Haul B. NCS-T. 132-139 m. : Pseudomma minutum sp.n.; Mysidopsis acuta Hansen. St. WS806. 7. i. 32 (day). Patagonian Shelf, north-west of Falkland Is. NCS-T. 123-130 m.: Pseudomma minu- tum sp.n. ? Types; Mysidopsis acuta Hansen. St. WS 809. 8. i. 32 (day). Patagonian Shelf, north-west of Falkland Is. NCS-T. 108-104 m-: Mysidopsis acuta Hansen. St. WS 816. 14. i. 32 (day). Patagonian Shelf, west of Falkland Is. N4-T. 150-150 m.: Mysidopsis acuta Hansen. St. WS 818. 17. i. 32 (day). Patagonian Shelf, west-south-west of Falkland Is. N 4-T. 272-278 m. : Hansenomysis falklandica sp.n. ; Pseudomma sarsi (W.-Suhm in MS.) G. O. Sars; Pseudomma minutum sp.n. ; Mysidetes macrops sp.n. St. WS 820. 18. i. 32 (night). South-west of Falkland Is. N 4-T. 351-368 m.: Hansenomysis falklandica sp.n. St. WS821. 18. i. 32 (day). South of Falkland Is. N 4-T. 461-468 m.: Hansenomysis falklandica sp.n. St. WS 834. 2. ii. 32 (day). Patagonian Shelf, west of Falkland Is. N7-T. 27-38111.: Neomysis patagona Zimmer. St. WS837. 3. ii- 32 (day). Patagonian Shelf. N 4-T. 102-102 m.: Mysidopsis acuta Hansen. St. WS839. 5- »• 32 (night). Patagonian Shelf, south-west of Falkland Is. N4-T. 503-534 m.: Hansenomysis falk- landica sp.n.; Boreomysis rostrata Illig; Amblyopsoides obtusa sp.n. Types; Mysidetes macrops sp.n. St. WS871. 1. iv. 32 (day). South-west of Falkland Is. BTS. 336-342 m. : Mysidetes macrops sp.n. St. WS976. 6. iii. 50 (day). Nearly 200 miles west of Walvis Bay. N 70 V. 100-50 m.: Euchaetomera intermedia Nouvel. 250-100 m. : Euchaetomera zurstrasseni Illig. 750-500 m. : Boreomysis rostrata Illig. 1000-750 m. : Dactylamblyops hodgsoni Holt and Tattersall; Katerythrops oceanae Holt and Tattersall. St. WS 977. 6/7. iii. 50 (night). Nearly 200 miles north-west of Walvis Bay. N 70 V. 250-100 m. : Euchaetomera tenuis G. O. Sars. 500-250 m. : Euchaetomera typica G. O. Sars; Caesaromysis hispida Ortmann. 750-500 m. : Boreomysis rostrata Illig. 18 DISCOVERY REPORTS St. WS 978. 7. iii. 50 (day). 150 miles west of Walvis Bay. N 70 V. 100-50 m. : Euchaetomera typica G. O. Sars; Enchaetomera intermedia Nouvel. 500-250 m.: Meterythrops sp.?. 750-500 m. : Boreomysis rostata Illig. St. WS 979. 7. iii. 50 (night). West of Walvis Bay. N 70 V. 100-50 m. : Boreomysis insolita sp.n. St. WS 986. 10. iii. 50 (day). West of Spencer Bay, South-west Africa. N 70 V. 50-0 m.: Arachnomysis leuckartii Chun. 1000-750 m. : Eucopia grimaldii Nouvel; Boreomysis rostrata Illig. St. WS 987. 10. iii. 50 (day). South-west of Walvis Bay. N 70 V. 50-0 m.: Boreomysis insolita sp.n. 250-100 m. : Boreomysis insolita sp.n. Types. St. WS 996. 12. iii. 50 (day). 200 miles west of Orange River estuary. N 70 V. 1000-750 m.: Boreomysis microps G. O. Sars. St. WS 998. 13. iii. 50 (day). West of Orange River estuary. N 70 V. 100-50 m., 175-100 m.: Leptomysis megalops Zimmer. St. WS 1000. 13. iii. 50 (night). About 100 miles west of Orange River estuary. N 70 V. 50-0 m. : Anchialina typica (Kroyer). 100-50 m. : Gastrosaccus sanctus (van Beneden); Anchialina typica (Kroyer); Leptomysis megalops Zimmer. 150-100 m. : Anchialina typica (Kroyer). St. WS 1001. 13/14. iii. 50 (night). West of Orange River estuary. N 70 V. 50-0 m. : Leptomysis larvae? megalops. St. WS 1002. 14. iii. 50 (night). 8 miles off Orange River estuary. N 70 V. 50-0 m. : Gastrosaccus sanctus (van Beneden). MARINE BIOLOGICAL STATION, SOUTH GEORGIA St. MS 19. 9. iv. 25 (day). 3 miles south-west of Merton Rock, East Cumberland Bay. NC 50 V. 120-80 m. : Mysidetes dimorpha sp.n. St. MS 20. 9. iv. 25 (day). i\ miles south-west x west of Merton Rock, East Cumberland Bay. NC 50 V. 200- 160 m. : Mysidetes microps sp.n. 40-0 m. : Antarctomysis maxima Holt and Tattersall (Hansen MS.). St. MS 22. 9. iv. 25 (day). 1-3 miles north of Dartmouth Point, East Cumberland Bay. NC 50 V. 40-0 m.: Antarctomysis maxima Holt and Tattersall. St. MS 23. 12. iv. 25 (day). East Cumberland Bay. NC 50 V. 220-160 m.: Mysidetes dimorpha sp.n. St. MS 26. 15. iv. 25 (day). East Cumberland Bay. Haul B. NC 50 H. 10 m. : Antarctomysis maxima Holt and Tattersall. St. MS 27. 29. iv. 25 (day). i\ miles south-west x west of Merton Rock, East Cumberland Bay. NC 50 V 160-120 m. : Mysidetes microps sp.n.; Antarctomysis maxima Holt and Tattersall. St. MS 32. 1. v. 25 (day). East Cumberland Bay, 4-I cables north-east of Hobart Rock to i| miles south-south-east of Hope Point. BTS. 40 m. : Antarctomysis maxima Holt and Tattersall. St. MS 62. 24. ii. 26 (day). East Cumberland Bay. BTS. 31 m.: Mysidetes dimorpha sp.n. St. MS 63. 24. ii. 26 (day). East Cumberland Bay, 1-3 miles south x east to i-6 miles south-east x south of Hope Point. BTS. 23 m.: Mysidetes dimorpha sp.n. $ Types. St. MS 65. 28. ii. 26 (day). East Cumberland Bay, i-6 miles south-east of Hobart Rock to 1 cable north of Dart- mouth Point. BTS. 39 m.: Mysidetes dimorpha sp.n. St. MS 66. 28. ii. 26 (day). East Cumberland Bay. 2 \ miles south-east of King Edward Point Light to ij cables west x north of Macmahon Rock. BTS. 18 m.: Mysidetes dimorpha sp.n. $ Types. St. MS 67. 28. ii. 26 (day). East Cumberland Bay. BTS. 38 m. : Mysidetes dimorpha sp.n. St. MS 68. 2. iii. 26 (day). East Cumberland Bay. NRL. 220-247 m.: Pseudomma armatum Hansen; Mysidetes kerguelensis Illig; Mysidetes microps sp.n.; Mysidetes macrops sp.n.; Mysidetes dimorpha sp.n.; Antarctomysis maxima Holt and Tattersall; Antarctomysis ohlini Hansen. St. MS 71. 9. iii. 26 (day). East Cumberland Bay, 9! cables east x south to 1-2 miles east x south of Sappho Point. BTS. 110-60 m.: Mysidetes microps sp.n. Antarctomysis maxima Holt and Tattersall. St. MS. 74. 17. iii. 26 (day). East Cumberland Bay, 1 cable south-east x south of Hope point to 3-1 miles south-west of Merton Rock. BTS. 22-40 m. : Mysidetes dimorpha sp.n. GEOGRAPHICAL DISTRIBUTION 19 GEOGRAPHICAL DISTRIBUTION This very rich collection has considerably extended our knowledge of the geographical distribution of most of the species represented in it. Although many of the species have been recorded from both northern and southern hemispheres, there is no definite evidence of bipolarity. On the contrary, a closer examination of the species, which had been regarded as common to the two hemispheres, has proved in several instances that those from southern waters differ from those of northern waters so consistently as to leave no doubt that they belong to different species. Hansen (1908, p. 100) suggested that as the specimens of Boreomysis scyphops G. O. Sars, which had been recorded from off the coasts of Finmark, did not agree with specimens which had been recorded under that name from the south-west of Australia, they should perhaps be referred to a different species. W. M. Tattersall (1951, p. 46), when studying the rich material of the United States National Museum, was able to confirm Hansen's observations and separated the southern specimens under the name B. inermis. He found that although this new species differed from the north European B. scyphops, it had a very wide distribution in the Pacific and occurred at many stations along the west coast of California and northward to the Behring Sea in the east, and in the Sea of Okhotsk in the north-west. The previous records were all from far south in the southern hemisphere, from the Weddell Sea, from near the Crozet Islands and from two stations to the south-west of Australia. The record in the Discovery collection is from South Georgia. B. inermis is bathypelagic and in all probability has a very wide distribution in the deep waters of the world. I think that the fact that it occurs so far north in the Pacific and so far south in the southern hemisphere points, not so much to an exhibition of bipolarity, but rather to the possibility that further exploration of the intermediate localities will reveal that it is present in the deeper waters. Its occurrence near South Georgia, so far north of its previous record from the Weddell Sea, supports this suggestion. Fage (1942, pp. 7-39) thoroughly revised all the literature and records concerning Lophogaster typicus — a species which was originally recorded from North European waters and which has since been recorded from such widely separated localities that it has been regarded as having a world-wide distribution. He found certain well-defined differences whereby these animals could be separated into four distinct species, and he noted further that these could be correlated with their geographical distribution. One of his new species, L. challengeri, which previously was only known from off Cape Town, is represented in the present collection. It was taken by the ships of the Discovery Investiga- tions at several stations around the south coast of South Africa and on three occasions off Cape Lopez. This extension northward of its known range may possibly be due to the influence of the Benguela Current, but until all the material recorded under the name of L. typicus has been re-examined, it is impossible to be sure that specimens of L. challengeri may not have been recorded from other localities as typicus. A careful comparison of the Discovery specimens with those of L. typicus from the west of Ireland fully bears out the observations made by Fage, and I accept L. challengeri as a valid species which is distinct from the northern L. typicus. Zimmer (1914, p. 392) founded the species Longithorax capensis on a single adult male from South African waters. Nouvel (1943, p. 75) doubtfully referred a damaged immature specimen from deep water off the Azores to this species and W. M. Tattersall (1951, p. 121) referred specimens from the Bermudas to the same species. Both authors recorded certain differences between their specimens and Zimmer's description of the type, but attributed these, in the one case to the immaturity and damaged condition of the specimens, and in the other to immaturity and difference in sex. A close examination of the records and figures, together with a study of the present material, has convinced me that Nouvel's specimen from the Azores and Tattersall 's from the Bermudas belong to the same species 3-2 2o DISCOVERY REPORTS which is not the same as Zimmer's Longithorax capensis from the southern hemisphere. I have sug- gested the name of Longithorax nouveli sp.n. for this species from the northern hemisphere. Many species in the Discovery collection are to be found in the tropical and temperate waters of both southern and northern hemispheres. A few, such as Gnathophansia gigas, G. zoea, G. ingens, Eucopia unguiculata, E. grimaldi, E. australis and Boreomysis rostrata appear to have a very wide distribution in all the oceans of the world, except the Arctic and Antarctic from which some of them have not yet been recorded. It is interesting to note that, at any rate as far as the Discovery collection is concerned, the species with the widest range are almost invariably very deep water forms and belong to the more primitive groups of the Mysidacea. One of the most remarkable captures of the whole collection is that of four specimens of Antarcto- mysis maxima at station 274, just south of the equator off St Paul de Loanda, Angola. This species has always been regarded as a purely Antarctic form. Its capture at many stations around the coasts of South Georgia and the Falkland Islands has extended its known geographical range considerably to the northward, but its occurrence in tropical waters off the west coast of Africa is most surprising. One other capture is worthy of especial comment, that of a species of My sis taken off the coast of South Georgia. This is the first time that any species of this genus has been recorded from the southern hemisphere. In order to show how far the Discovery collection has extended our knowledge of the distribution of mysids in the southern seas, I have drawn up a list of new records and, for purposes of comparison, I give also lists of those species which are known so far from the Atlantic Ocean only, from the Antarctic and Southern Seas only and from the Atlantic and Indian Oceans only. Full details of localities and the vertical distribution of species are given in the List of Stations and a note on the distribution is given at the end of the record of each species. NEW RECORDS IN THE DISCOVERY COLLECTION AND OTHER EXTENSIONS OF KNOWN RANGE (Locality given in brackets) Chalaraspidum alatum. New to South Atlantic (west of Cape Town). Gnathophausia ingens. New to western South Atlantic (off La Plata); new to southern temperate waters (Prince Edward Is. and off South Africa). Gnathophausia gigas. Range extended considerably to southward in South Pacific (Bellingshausen Sea). Gnathophausia zoea. New to central South Atlantic (west of Tristan da Cunha). Gnathophausia gracilis. New to southern hemisphere (off St Helena). Lophogaster schmidti. New to Indian Ocean (Arabian Sea, off Ras Hafun). Lophogaster challenged. Range extended considerably northward in eastern South Atlantic (off Cape Lopez). Eucopia sculpticauda. Range extended southward in Indian Ocean (off East London and Durban). Boreomysis rostrata. First record from surface waters; range considerably extended southward in Indian Ocean (off Heard Island). Boreomysis sibogae (doubtfully). New to South Atlantic (west of Cape Town and off South Georgia). Boreomysis atlantica. New to southern hemisphere (off Cape Town and off South Georgia). Boreomysis inermis. Range extended considerably northward in South Atlantic (South Georgia). Rhopalophthalmus egregius. Range extended northward in eastern South Atlantic (off Cape Lopez) and westward (off South Georgia). Gastrosaccus sanctus. New to southern hemisphere (off west coast of South Africa and off South Georgia). Anchialina truncata. Range extended considerably northward in eastern South Atlantic (off Cape Lopez). Anchialina typica. New to eastern South Atlantic (Benguela Current). Gibberythrops acanthura. Range extended considerably southward in western Indian Ocean (off Durban). Meterythrops picta. New to Indian Ocean (south of Madagascar). 21 GEOGRAPHICAL DISTRIBUTION Echinomysis chuni. Range extended southward in South Atlantic (Tristan da Cunha), new to western Indian Ocean (off Ras Hafun). Longithorax capensis. Range extended westward in South Atlantic (off Tristan da Cunha). Euchaetomera typica. Range extended considerably southward in Indian Ocean (north of Amsterdam Island). Euchaetomera tenuis. Range extended considerably southward in South Atlantic (South Africa). Euchaetomera glyphidophthalmica. New to southern hemisphere (off west coast of Africa from Orange River estuary to Cape Lopez). Euchaetomera intermedia. Range extended very considerably southward in Atlantic. First record south of equator in Atlantic (South Africa). Mysidetes kerguelensis. New to South Atlantic (South Georgia). Leptomysis apiops. First record outside Mediterranean Sea (off Cape Lopez). Leptomysis megalops. First record outside Mediterranean Sea (off west coasts of Central and South Africa from Cape Lopez to Cape Town). Afromysis hansom. First record free swimming in plankton — previous records from stomach of Trigla capensis. Antarctomysis maxima. Range extended northward in South Atlantic (South Georgia and one record from St Paul de Loanda). Antarctomysis ohlini. Range extended northward in South Atlantic (South Georgia). RECORDS FROM THE ATLANTIC OCEAN (NORTH AND SOUTH) AND MEDITERRANEAN SEA Species Previous records Discovery records, extending known range Lophogaster challenged South of Cape of Good Hope Around coasts of South Africa to Cape Lopez L. spinosus Warm waters of North and South Atlantic in open ocean Open ocean east of Rio de Janeiro Boreomysis atlantica Azores Cape Town, Tristan da Cunha, north- east of South Georgia Gastrosaccus sanctus Europe, Mediterranean, Morocco, Canaries, Cape Town, South-west Africa, South Gulf of Guinea Georgia Anchialirui truncata Off Cape Town South and south-west coasts of Cape Province, Cape Lopez Longithorax capensis Off Cape Town and east of Cape Verde Is. Cape Town to Tristan da Cunha Pseudomma armatum South Georgia South Georgia and South Orkney Is. Euchaetomeropsis merolepis Mediterranean, Gulf of Guinea, South Atlantic Eastern South Atlantic Arachnomysis megalops Gulf of Guinea, St Paul de Loanda, south- west of Sierra Leone Widely distributed in South Atlantic Leptomysis apiops Mediterranean only Off St Paul de Loanda, off Cape Lopez L. capensis South Africa and off Cape Lopez Cape Lopez, coasts of Cape Province L. megalops Mediterranean only West coasts of Central and South Africa from Cape Lopez to Cape Town Afromysis hansom Stomach of fish in Walvis Bay Stomach of fish in Walvis Bay and free off Cape Lopez Mysidetes crassa North and west of Falkland Is. Falkland Is., Patagonian Shelf Mysidopsis similis Off Angra Pequena, off coast of Cape Colony Off Cape Town Mysidopsis acuta Falkland Is., east of Cape Horn Falkland Is., east of Strait of Magellan M. schultzei Off Angra Pequena Off Cape Town M. major Off Angra Pequena Off Cape Town Neomysis monticelli Strait of Magellan East of Patagonia, east end of Strait of Magellan N. patagona East of South Patagonia, Strait of East of Tierra del Fuego, Strait of Magellan Magellan Arthromysis magellanica Strait of Magellan Strait of Magellan and east of Patagonia 22 DISCOVERY REPORTS RECORDS FROM THE SOUTHERN OCEAN AS FAR NORTH AS SOUTH GEORGIA Species Previous Records Discovery records extending known range Hansenomysis antarctica Circumpolar distribution in very cold waters south of 640 S. Schollaert Channel (within known range) Boreomysis brucei Weddell Sea South Shetland Is., South Orkney Is. and Palmer Archipelago B. inermis Weddell Sea and ? South Pacific South Georgia — extends known range to northward Pseudomma armatum South Georgia South Georgia and South Orkney Is. P. antarcticum Bellingshausen Sea South Shetland Is. and Palmer Archipelago P. sarsi Kerguelen Is., south of South Georgia Patagonian Shelf, South Shetland Is. South Orkney Is., Palmer Archipelago P. belgicae Antarctic Palmer Archipelago, Bay of Whales Dactylamblyops hodgsoni Circumpolar in very cold waters South Shetlands, South Sandwich Is., Ice Edge, south of South Georgia Euchaetomera zurstrasseni South Georgia, Falkland Is. and ? off Graham Land, Bellingshausen Sea, Ice Seychelles Edge, South Africa Mysidetes posthon Circumpolar in Southern Seas South Georgia, South Shetland Is., Falk- land Is., South Sandwich Is. M. crassa North and west of Falkland Is. Falkland Is., Patagonian Shelf M. brachylepis Ross Sea South Georgia, South Shetland Is., north of Falkland Is. Mysidopsis acuta Falkland Is., off Tierra del Fuego Falkland Is., east of Strait of Magellan Neomysis patagona Magellan Strait, South Patagonian Shelf Magellan Strait, north-east of Tierra del Fuego N. monticellii Strait of Magellan East of Strait of Magellan Antarctomysis maxima Antarctic only Falkland Is., Scotia Sea, Bay of Whales, off St Paul de Loanda A. ohlini Antarctic, Ross Sea, South Georgia Falkland Is., Scotia Sea, South Orkney Is., Bay of Whales Arthromysis magellanica Strait of Magellan Strait of Magellan and Patagonian Shelf Atlantic and Atlantic and Pacific and Indian Ocean only Indian Oceans Pacific Oceans Indian Oceans Lophogaster rotundatus Petalophthalmus oculatus Boreomysis plebeja Lophogaster schmidti Pseudomma sarsi B. rostrata Boreomysis sibogae Katerythrops oceanae Siriella gracilis Echinomysis chuni S. aequiremis Euchaetomera typica Gibberythrops acanthura E. zurstrasseni Euchaetomera oculata E. glyphidophthalmica E. intermedia Caesaromysis hispida Arachnomysis leuckartii Mysidetes kerguelensis LIST OF NEW SPECIES WITH THEIR LOCALITIES 23 LIST OF NEW GENERA AND SPECIES AND THE LOCALITIES WHERE THEY OCCURRED Eucopia Unguicauda. Open ocean west of Saldanha Bay, Natal. Eucopia sp. West of Sierra Leone. Hansenomysis falklandica. Around the Falkland Is. Boreomysis illigi. Cape Verde Is., Canaries, Arabian Sea, Cape Town. Boreomysis tattersalli. Arabian Sea. Boreomysis bispinosa. Off Cape Town, St Helena, South Georgia. Boreomysis insolita. Walvis Bay, South-west Africa. Boreomysis acuminata. South and south-west of Sierra Leone, east and north-east of St Helena. Pseudomma calmani. North of Falkland Is. Pseudomma sc/iollaertensis. Palmer Archipelago. Pseudomma longicaudum. Schollaert Channel, Palmer Archipelago. Pseudomma magellanensis. Strait of Magellan. Pseudomma minutum. Falkland Is. Amblyops durbani. Off Durban. Amblyops antarctica. South Shetland Is. and Bay of Whales. Amblyops sp. near kempi. Strait of Magellan. Amblyopsoides obtusa. Strait of Magellan. Paramblyops brevirostris. Schollaert Channel, Palmer Archipelago. Gibberythrops megalops. West of Cape Town. Katerythrops resimora. Off Cape Town. Heteroerythrops purpura. Off Angra Pequena, South-west Africa. Erythrops africana. Off Cape Lopez. Mysidetes microps. South Georgia. Mysidetes macrops. Falkland Is. and South Georgia. Mysidetes intermedia. Falkland Is. and Strait of Magellan. Mysidetes patagonica. Strait of Magellan, Patagonian Shelf, Falkland Is. Mysidetes anomala. Strait of Magellan. Mysidetes dimorpha. South Georgia and Palmer Archipelago. Mysidopsis camelina. False Bay, South Africa. Mysis australe. South Georgia. Longithorax nouveli. Azores and Bermudas. (See pp. 126-127 I°r discussion.) Order MYSIDACEA The order Mysidacea falls naturally into two clearly distinct groups which differ so profoundly from one another that they have been given the status of suborders under the names Lophogastrida and Mysida. The Lophogastrida show the following primitive characters which are absent in nearly all the Mysida: (1) Large foliaceous gills present on the thoracic appendages. (2) No statocyst on the endopod of the uropod. (3) Pleopods of both sexes biramous, multiarticulate, natatory and unmodified. (4) Marsupium composed of seven pairs of imbricating brood lamellae. (5) Well-developed pleural plates present on the abdominal somites. (6) A more or less well-marked transverse groove encircling the last abdominal somite and marking the incomplete fusion of the sixth and seventh abdominal somites of the embryo. A pair of lateral teeth immediately in front of this groove marks the postero-ventral angle of the sixth abdominal somite of the fossil forms and of the embryo. 24 DISCOVERY REPORTS The Mysida in some cases show traces of primitive characters as, for example, the presence of pleural plates on the first abdominal somite of the females in the Gastrosaccinae, and of the males in the genus Rhopalophthalmas, and the absence of a statocyst in the Petalophthalmidae. The classification of the Mysidacea adopted in the present work is that drawn up by Hansen (19 10, pp. 8-77), in which the more primitive forms are considered first and the more complex later according to their degree of specialization. LIST OF MYSIDACEA IN THE DISCOVERY COLLECTIONS ARRANGED IN SYSTEMATIC ORDER (with synonymies) Order MYSIDACEA Suborder Lophogastrida Family LOPHOGASTRIDAE Genus Chalaraspidum W.-Suhm, 1895 (from MS. dated 1874) = Chalaraspis W.-Suhm, 187 5 = Eclytaspis Faxon, 1895. Chalaraspidum alatum W.-Suhm (in MS. 1874) = Chalaraspis alata. Genus Gnathophausia W.-Suhm, 1873. Gnathophausia ingens (Dohrn), 1870 = 6'. inflata W.-Suhm, i873 = G. calcarata G. O. Sars, i885 = G. bengalensis Wood-Mason and Alcock, 1891= G. doryphora Illig, 1906. Gnathophausia gigas W.-Suhm, 1873 = G. drepanephora Holt and Tattersall. Gnathophausia zoea W.-Suhm, 1873 = G. willemoesii G. O. Sars, 1885 = G. sarsi Wood-Mason and Alcock, 1891. Gnathophausia gracilis W .-Suhm, 1875 = G. brevispinis Wood-Mason and Alcock, 1891 =G. dentata Faxon, 1893 = G. bidentata Illig, 1906. Genus Lophogaster M. Sars, 1857 = Ctenomysis Norman, 1862. Lophogaster challenged Fage, 1942 = /,. typicus G. O. Sars, 1885. Lophogaster spinosus Ortmann, 1906. Lophogaster rotundatus Illig, 1930 = /,. typicus var. Tattersall, 1911. Lophogaster schmidti Fage, 1941. „ . „ „ Family EUCOPIIDAE Genus hucopia Dana, 1852. J Eucopia unguiculata (W.-Suhm), 1875 = 2?. australis (pars) G. O. Sars, 1885 = 2?. hanseni Nouvel, 1942. Eucopia grimaldii Nouvel, 1942. Eucopia australis Dana, 1852 = 2?. major Hansen, 19 10. Eucopia sculpticauda Faxon, 1893 = 2?. equatoria Spence-Bate, 1885 = 2?. intermedia Hansen, 19 10. Eucopia linguicauda sp.n. Suborder Mysida Family PETALOPHTHALMIDAE Genus Hansenomysis Stebbing, 1893= Arctomysis Hansen, 1887. Hansenomysis antarctica Holt and Tattersall, 1906. Hansenomysis falklandica sp . n . Genus Petalophthalmus W.-Suhm, 1875. Petalophthalmus oculatus Illig, 1906. LIST OF SPECIES IN SYSTEMATIC ORDER, WITH SYNONYMIES 25 Family Mysidae Subfamily BOREOMYSINAE Genus Boreomysis G. O. Sars, 1869 = Petalophthalmus (pars) W.-Suhm, 187 5 = Arctomysis Czerniavsky, 1883 = Pseudanchialus Caullery, 1896. Boreomysis rostrata Illig, 1906 = 5. inermis Hansen, 1910. Boreomysis illigi sp.n. = 5. rostata (pars) Illig, 1906. Boreomysis plebeja Hansen, 1910. Boreomysis sibogae Hansen, 1910 = B. spinifera Coifmann, 1936. Boreomysis brucei Tattersall, 19 13. Boreomysis atlantka Nouvel, 1942. Boreomysis microps G. O. Sars, 1884 = 5. subpellucida Hansen, 1905. Boreomysis tattersalli sp.n. Boreomysis bispinosa sp.n. Boreomysis inermis (W.-Suhm) as Petalophthalmus inermis W.-Suhm, 1874 = Petalophthalmus armiger W.-Suhm, 1875 = 5. scyphops G. O. Sars, 1884 = 5. suhmi Faxon, 1893 = 5. distinguenda Hansen, 1908. Boreomysis insolita sp.n. Boreomysis acuminata sp.n. Subfamily Siriellinae Genus Siriella Dana, i8^o = Cynthia Thompson, 1829 = Cynthilia White, i8$o = Promysis Kroyer, iS6i=Proto- siriella, 1882 = Siriellides, 1882 = Rhinomy sis, 1882 = Heterosiriella Czerniavsky, 1883 = Pseudosiriella Claus, 1884. Siriella thompsonii (Milne-Edwards), 1837 = 5. vitrea Dana, 1852 = 5. brevipes Dana, 1852 = 0. inermis Kroyer, i86i = 5. edwardsii Claus, 1868 = 5. indica Czerniavsky, 1882. Siriella gracilis Dana, 1852. Siriella aequiremis Hansen, 19 10. Subfamily Rhopalophthalminae Genus Rhopalophthalmus Illig, 1906. Rhopalophthalmus egregius Hansen, 1910. Subfamily Gastrosaccinae Genus Gastrosaccus Norman, 1868 = Acanthocaris Sim, 1872 = Haplostylus Kossmann, 1880 = Pontomysis Czer- niavsky, 1882 = Chlamydopleon Ortmann, 1892. Gastrosaccus sanctus (van Beneden), 1861 =Mysis sancta van Beneden. Genus Anchialina Norman and Scott, 1906 = Anchialus Kroyer, 1861. Anchialina typica (Kroyer), 1861. Anchialina truncata (G. O. Sars), 1884. Subfamily MYSINAE Tribe ERYTHROPINI Genus Pseudomma G. O. Sars, 1870. Pseudomma armatum Hansen, 1913. Pseudomma sarsi (W.-Suhm in MS.) G. O. Sars, 1884. Pseudomma antarcticum Zimmer, 1914. Pseudomma belgicae (Hansen in MS.) Holt and Tattersall, 1906. Pseudomma calmani sp.n. Pseudomma schollaertensis sp.n. Pseudomma longicaudum sp.n. Pseudomma magellanensis sp.n. Pseudomma minutum sp.n. 26 DISCOVERY REPORTS Genus Amblyops G. O. Sars, 1872 = Amblyopsis G. O. Sars, 1869. Amblyops dttrbani sp.n. Amblyops antarctica sp.n. Amblyops sp. near A. kempt Tattersall, 1905. Genus Amblyopsoides gen.n. Amblyopsoides obtusa sp.n. Genus Paramblyops Holt and Tattersall, 1905. Paramblyops brevirostris sp.n. Genus Dactylamblyops Holt and Tattersall, 1906. Dactylamblyops hodgsoni Holt and Tattersall, 1906 = Dactylerythrops arcuata Illig, 1906. Genus Gibberythrops Illig, 1930. Gibberythrops acanthura (Illig), 1906 = Parerythrops acanthura Illig, 1906. Gibberythrops megalops sp.n. Genus Meterythrops S. I. Smith, 1879 = Parerythrops (pars) G. O. Sars, 1879. Meterythrops picta Holt and Tattersall, 1905. Genus Katerythrops Holt and Tattersall, 1905. Katerythrops oceanae Holt and Tattersall, 1905 = K. dactylops Illig, 1906. Katerythrops resimora sp.n. Genus Heteroerythrops gen.n. Heteroerythrops purpura sp.n. Genus Erythrops G. O. Sars, 1869 = Nematopus G. O. Sars, 1863. Erythrops africana sp.n. Genus Echinomysis Illig, 1905. Echinomysis chuni Illig, 1905. Genus Longithorax Illig, 1906. Longithorax capensis Zimmer, 19 14. Genus Euchaetomera G. O. Sars, 1883 = Brutomysis Chun, 1896 = Mastigophthalmus Illig, 1906. Euchaetomera typica G. O. Sars, 1884 = ^. vogtii Chun, i896 = £'. limbata Illig, 1906 = 5. sennae Colosi, 1918. Euchaetomera tenuis G. O. Sars, 1883 = Brutomysis Chun, 1896 = E. fowleri Holt and Tattersall, 1905. Euchaetomera zurstrasseni (Illig), 1906 as M. zurstrasseni = E. pulchra Hansen, 1913. Euchaetomera glyphidophthalmica Illig, 1906. Euchaetomera oculata Hansen, 1910. Euchaetomera intermedia Nouvel, 1942. Genus Euchaetomeropsis W. M. Tattersall, 1909. Euchaetomeropsis merolepis (Illig), 1908. Genus Caesaromysis Ortmann, 1893. Caesaromysis hispida Ortmann, 1893. Genus Arachnomysis Chun, 1887. Arachnomysis leuckartii Chun, 1887. Arachnomysis megalops Zimmer, 19 14. Tribe leptomysini Genus Mysidetes Holt and Tattersall, 1906=? Mysidopsis G. O. Sars, 1885 = Mysideis (pars) Holt and Tattersall, 1905 = Metamysidella Illig, 1906. Mysidetes posthon Holt and Tattersall, 1906. Mysidetes kerguelensis (Illig), 1906 as Metamysidella kerguelensis. Mysidetes crassa Hansen, 1913. Mysidetes brachylepis Tattersall, 1923. LIST OF SPECIES IN SYSTEMATIC ORDER, WITH SYNONYMIES 27 Genus Mysidetes microps sp.n. Mysidetes macrops sp.n. Mysidetes intermedia sp.n. Mysidetes patagonica sp.n. Mysidetes anomala sp.n. Mysidetes dimorpha sp.n. Genus Mysidopsis G. O. Sars, 1864 = Paramysidopsis Zimmer, 191 2. Mysidopsis acuta Hansen, 1913. Mysidopsis similis (Zimmer), 1912 as Paramysidopsis similis. Mysidopsis major (Zimmer) as Paramysidopsis major, 1912. Mysidopsis schultzei (Zimmer) as Paramysidopsis schultzei, 1912. Mysidopsis camelina sp.n. Genus Leptomysis G. O. Sars, 1869. Leptomysis apiops G. O. Sars, 1877. Leptomysis capensis Ulig, 1906. Leptomysis megalops Zimmer, 191 5. Genus Afromysis Zimmer, 1916. Afromysis hansom Zimmer, 1916. Tribe MYSINI Genus Mysis Latreille, 1802-3 = Megalophthalmus Leach, ifyo = Onychomysis Czerniavsky, 1882 = Michtheimysis Norman, 1 902 = Mesomysis Norman, 1905 = Pugetomysis Banner, 1953. Mysis australe sp.n. Genus Neomysis Czerniavsky, 1882 = Heteromysis Czerniavsky, 1882. Neomysis patagona Zimmer, 1907. Neomysis monticellii Colosi, 1924. Genus Antarctomysis Coutiere, 1907. Antarctomysis maxima (Hansen in MS.) Holt and Tattersall, 1906. Antarctomysis ohlini Hansen 1908 = Antarctomysis sp. Tattersall, 1908. Genus Arthromysis Colosi, 1924. Arthromysis magellanica (Cunningham), 1871 as Macromysis magellanica = Antarctomysis sp. Zimmer, 19156 = Arthromysis chierchiae Colosi, 1924. SYSTEMATIC REPORT Order MYSIDACEA Suborder Lophogastrida Family LOPHOGASTRIDAE Genus Chalaraspidum W.-Suhm 1874 Chalaraspis W.-Suhm, p. 592. 18856 Chalaraspis, G. O. Sars, p. 50. 1895 Chalaraspidum W.-Suhm (in Murray, 1895, p. 521, from MS. dated 1874). 1895 Eclytaspis Faxon, p. 219. 1 89 1 Chalaraspidum, W. M. Tattersall, p. 13. Remarks. The genus Chalaraspidum very closely resembles Lophogaster, but may be distinguished from it by the form of the rostral plate which is broad and relatively short, with the transverse anterior margin either quite straight or very slightly emarginate in its median region. There is no trace of the tndentate form which is so characteristic of Lophogaster, but the antero-lateral angles may, at least in the females, be produced into an acute process on each side. The anterior margin and the lateral 4-2 28 DISCOVERY REPORTS margins which cover the eyes may be more or less serrated and there may be scattered spinules on the carapace behind and below the eyes. The eyes are much reduced and very long, extending laterally at right angles to the main axis of the body, with the distal half of the cornea extending beyond the lateral margins of the rostral plate. There is a small, curved, finger-like ocular papilla on the inner distal margin of the eyestalk. The uropods are relatively longer than in Lophogaster and the outer margin of the exopod is armed with two or three small spines in addition to the terminal one. Only one species, Chalaraspidum alatum, has been recorded up to the present, but Zimmer (1914, p. 383) obtained a specimen from near the Azores which undoubtedly belongs to the genus. Owing to its damaged condition, Zimmer did not feel justified in founding a new species for it, but the form of the antennal scale which he figured and the shape of the telson indicate that in all probability it is a new species of Chalaraspidum. Chalaraspidum alatum (W.-Suhm) in MS. 1874 (Fig. 1 A-E) 1874 Chalaraspis alata W.-Suhm, p. 592. 18856 Chalaraspis alata, G. O. Sars, p. 51, figs. 1895 Chalaraspidum alatum W.-Suhm (in Murray, 1895, p. 521 from MS. dated March, 1874). 1895 Eclytaspis alata, Faxon, p. 219. 1 91 2 Chalaraspis alata, Hansen, p. 182, figs. 1939 Chalaraspis alata, Fage, p. 68, figs. 1 941 Chalaraspis alata, Fage, p. 4, figs. 195 1 Chalaraspidum alatum, W. M. Tattersall, p. 14. Occurrence : St. 101. 14/15. x. 26 (night). West of Cape Town, 2580-2480 m., 1 imm. $, 28 mm., with very small oostegites. St. 253. 21. vi. 27 (day). About 1000 miles west of Cape Peninsula, 1050-1000 m., 1 adult $, 38 mm. Remarks. Owing to the softness of the integument and to the great depths at which specimens have been taken, there are no records of a perfect example of this interesting species. The type had unfortunately been lost by the time Sars wrote his report on the Challenger Schizopods and his description of the species was compiled from the notes and letters written by Dr Willemoes-Suhm some eleven years earlier. The figures Sars gave were faithful copies of manuscript sketches made by W.-Suhm. Since its original discovery a few records of the species have been made from widely separated localities in the Pacific, and details of the morphology have been added. In some respects these later descriptions do not agree with that given by W.-Suhm and some suggestion has arisen that there may be more than one species involved. The description of the rostral plate of the type is as follows : 'Anteriorly, it (the carapace) projects as a short, but very broad, frontal plate, abruptly truncate at the extremity, the anterior margin being slightly emarginate and finely serrate, the lateral corners somewhat extended.' Hansen (1912, p. 182), recording several immature specimens from the eastern Pacific off Peru, stated that the antero- lateral corners of the rostral plate were broadly rounded. He made no mention of any serrulations along the anterior or lateral margins and, if they were present, it is most unlikely that so meticulous a worker would have overlooked them. Fage (1939, p. 68), recording specimens from the China Sea and from the Gulf of Panama, stated that the antero-lateral angles were rounded and very finely serrulated. Both authors recorded that the outer margin of the antennal scale was armed with 9-12 teeth in addition to the distal terminal tooth. Tattersall (1951) recorded three specimens captured in the Pacific by the 'Albatross'. He stated that one of these, taken in the East Pacific off the coast of California, agreed very closely with the SYSTEMATIC REPORT 29 descriptions and figures given by Hansen and Fage, but that the other two, which were captured off the south coast of Japan, differed as follows: '(1) The rostral plate has the outer antero-lateral angles drawn out into conspicuous spines ; the margin between these spines is slightly concave in the centre and is microscopically serrulated; there are three or four spinules on the lateral margins of the rostral plate on each side and a prominent ocular spine on the carapace margin over the eye ; there are also scattered microscopic spinules on the lateral area of the carapace below and behind the eyes. (2) The outer margin of the antennal scale has only three or four teeth in addition to the terminal tooth.' A glance at Fig. 1 A will show how very closely the Discovery specimens agree with this description — the only difference being that in them the serrations, which adorn the margins of the rostral plate, would appear to be coarser and probably fewer in number than in Tattersall's specimens. My figure is taken from the smaller of my two specimens. The larger animal is badly damaged, but the margins of the rostral plate are quite clear and show that there are rather more serrulations than in the smaller specimen, but not so pronounced. It is probable that there is considerable individual varia- tion in this character. In both my specimens the outer margin of the antennal scale bears only two or three teeth in addition to the terminal one. Hansen (19 12) recorded that the apex of the telson in his specimens was truncate and lacked spines or hairs, adding that it was possible that these may have been lost. Fage (1939, 1 941) recorded that the apex of the telson in his specimens was straight and armed with four short spines. Tattersall (1951) stated that both of his Japanese specimens had seven spines on each of the lateral margins of the telson and that in one of them the armature of the apex was almost intact, showing ' four rather stout and closely set spines, the inner pair nearly twice as long as the outer pair '. The two specimens in the Discovery collection indicate very strongly, at least as regards the telson, that previously recorded variations can be attributed to the damaged con- dition of the material available. In the larger Discovery specimen all the spines of the telson are missing, but there are seven notches on each lateral margin indicating where the spines were borne and the apex presents an appearance strikingly like that figured by Fage (1942) for his specimen. I feel convinced that the 'four small spines' which he noticed are really the broken pieces of the original armature of the telson apex. The smaller Discovery specimen has the telson intact, except for the loss of one of the larger apical spines. The high serrulated keels are in perfect condition and are exactly like those figured by Hansen (1912) for his specimen (Fig. 1 D-E). It would thus appear that specimens hitherto referred to this species fall into two definite groups : (1) with the rostral plate serrulated along its anterior (and lateral) margins, the antero-lateral angles produced into acute processes and with the outer margin of the antennal scale armed with only Fig. 1. Chalaraspidum alatum (W.-Suhm). A, ante- rior end of immature female; B, right eye in dorsal view; C, labrum; D, telson and left uropod in dorsal view; E, telson in lateral view. All xo,. 30 DISCOVERY REPORTS 2-4 teeth, and (ii) with the anterior margin of the rostral plate smooth, the antero-lateral angles rounded (in Fage's description minutely serrulated) and with the outer margin of the antennal scale armed with 9-12 serrations. It may be that these two groups do represent two separate species, but Tattersall (1951) put forward the interesting suggestion that the differences between the groups might be sexual. He noted that the Challenger specimen was a female and that all the specimens examined by Hansen and Fage were male. All his own specimens were too immature for their sex to be ascertained, so that he was unable to obtain any evidence from them. Unfortunately both the Discovery specimens are female, but it is significant that they agree with the Challenger specimen, which was also a female. The eyes in this species are very long and slender, nearly four times as long as broad. The cornea is no wider than the eyestalk and occupies about one-fourth of the whole organ. There is a well-marked finger-like ocular papilla on the distal inner margin of the eyestalk. Hansen figured a papilla in this position but made no mention of it in the text (Fig. 1 B). The labrum is flask-shaped and quite symmetrical, with its anterior end produced forward into a long acute process (Fig. 1 C). Distribution. Chalaspidum alatum is known to have a very wide distribution in the deep waters of the Pacific. Since the type was taken in the Indian Ocean, off Kerguelen Island it has been recorded from four stations in the East Pacific, off the west coast of Peru (Hansen, 191 2), from the China Sea, north of New Guinea and from the Gulf of Panama (Fage, 1939, 1941) and from two stations to the south of Japan and one to the west of San Diego, California (Tattersall, 195 1). Its occurrence in the South Atlantic considerably extends its known geographical range. The record of the type simply gives the depth as 1800 fm. and it is not stated whether a closing net was used. Hansen's specimens were taken in vertical hauls of 300 and 400 fm. to the surface. The records of the ' Dana ', giving the length of the cable out and the depth of water over which it was fishing, indicate that the animals were living between depths of 300 m. and 2500 m. The capture of an immature female in a closing net fishing between 2400 m. and 2500 m. at Discovery station 101, and of an adult in a net fishing between 1050 m. and 1000 m. at Discovery station 253 proves that the species can live at great depths. The robust abdomen and the strongly developed pleopods suggest that it is a powerful swimmer and that in all probability its vertical range is considerable. Genus Gnathophausia W.-Suhm, 1873 1873 Gnathophansia (lapsus calami) W.-Suhm, p. 400. 1874 Gnathophausia, Humbert, p. 206. Remarks. The genus Gnathophausia very closely resembles the fossil genus Tellocaris (Peach, 1908, p. 9) as regards the telson, but even more closely in the form and armature of the carapace with its anterior margin serrated and produced into a long dentate rostrum and the posterior margin produced into a long median dorsal spine which is also frequently dentate. This spine is always present in young specimens and usually persists as a long projection, but in some species it becomes progressively shorter as the animals approach maturity and in large specimens may almost disappear. The chief generic characters are the tough, parchment-like integument ; the large, shield-like cara- pace adorned with strong raised keels which are often toothed; rostrum long and sharp with three longitudinal, dentate ridges making it triangular in section ; posterior margin of carapace produced into a strong median spine; pleural plates of abdominal somites bilobed; eyes with well-developed papilla; sixth abdominal somite with well-marked groove running around its median region; maxillule with a two-segmented, setose, backwardly reflexed endopod ; first thoracic exopod absent or reduced to a small unsegmented plate; exopod of uropod broad, two-segmented, outer margin of proximal seg- ment naked and terminated by a strong spine ; telson entire with a strong constriction near the apex which is armed with two very strong curved spines which together form a backwardly directed crescent. SYSTEMATIC REPORT 3I Eight species have up to the present been referred to this genus, Gnathophausia ingens (Dohrn), gigas W.-Suhm, zoea W.-Suhm, gracilis W.-Suhm, elegans G. O. Sars, longispina G. O. Sars, affinis G.O. Sars and scapularis Ortmann. These species fall very sharply into two groups according to the form of the antennal scale. In ingens and gigas the scale is lanceolate and unsegmented with an acutely pointed apex and with the outer margin armed with teeth. In the other six species the scale resembles that found in the Caridea. The outer margin is thickened to form a strong rib which is produced distally into a spine from the base of which an oblique suture runs across the scale. The outer margin bears a number of teeth and in one species the spine of the outer margin is dentate on both its margins. A second character which separates ingens and gigas from the other species of the genus is the peculiar modification of the epimeral plates of the last abdominal somite. In the young, these are separate and distinct as in other species of Gnathophausia, but in ingens and gigas, as growth proceeds, they bend under the body to fuse eventually in the median line into a single epimeral plate. The differences between the species are so marked that they might be considered as of generic significance, ingens and gigas being placed in a separate genus, were it not for the fact that another very profound difference occurs among the species which would divide the genus in quite another way. In ingens, gigas and gracilis the exopod of the first thoracic appendage is present in the form of a small, slender, unsegmented plate, adorned distally with a few very long plumose setae. In the remaining known species of the genus the exopod of this appendage is completely lacking, but its position is marked on the sympod by a shallow oval depression. If any subdivision of the genus were to be made, it would be logical to arrange the species into three distinct subgenera, separating ingens and gigas into a subgenus based on the form of the antennal scale, the ventral epimeral plate of the last abdominal somite and the presence of an exopod on the first thoracic appendage ; placing zoea, longispinis, elegans and scapularis in a second based on the form of the antennal scale, the separate epimera of the sixth abdominal somite and the absence of an exopod on the first thoracic appendage ; and gracilis in a third subgenus by itself, resembling the first in the form of the scale and epimera of the last abdominal somite and the second in having an exopod on the first thoracic appendage. While so few species are included in the genus there is not much point in changing the present nomenclature, but if further exploration of the deep waters of the oceans should reveal many new forms there would be ample grounds for the division of the genus into subgenera. The genus Gnathophausia includes the largest mysids which have ever been recorded. All the known species are bathypelagic and no specimen has ever been taken at the surface or in very shallow water. Only four of the known species have been collected by the ' Discovery ' : G. ingens (Dohrn), G. gigas W.-Suhm, G. zoea W.-Suhm and G. gracilis W.-Suhm. Gnathophausia ingens (Dohrn), 1870 1870 Lophogaster ingens Dohrn, p. 610, figs. 1873 Gnathophausia inflata W.-Suhm, in MS. 1885 a Gnathophausia ingens, G. O. Sars, p. 30, figs. 1885 a Gnathophausia calcarata G. O. Sars, p. 35, figs. 18916 Gnathophausia bengalensis Wood-Mason, J., and Alcock, A., p. 269. 19066 Gnathophausia doryphora Illig, p. 227; 1930, p. 407, figs, (as G. ingens). 1906 Gnathophausia ingens, Ortmann, p. 28. 1912 Gnathophausia ingens, Hansen, p. 184; 1927, p. 15, figs. 195 J Gnathophausia ingens, W. M. Tattersall, p. 25. 33 discovery reports Occurrence : 10. x. 25. 410 37' 15" N., 12° 36' 20" W. North-east of Azores, 0-900 m., 1 juv. 92 mm. St. 76. 5. vi. 26 (day). 390 50' 30" S., 360 23' 00" W., i50o(-o) m., 1 juv. 38 mm. St. 81. 18. vi. 26 (day). 32° 45' 00" S., 8° 47' 00" W. Mid-Atlantic between Cape Town and Monte Video, 65o(-o) m., 1 juv. 38 mm. St. 86. 24. vi. 26 (day). 330 25' 00" S., 6° 31' 00" E. West of Cape Town, iooo(-o) m., 1 <$, 96 mm. (eye to telson). ('Deep scarlet red throughout, palest on scales, uropods and protopodites of pleopods'), 1 imm. $, 60 mm., 1 juv. 50 mm. St. 100B. 3. x. 26 (night). West of Cape Town, 1000-900 m., 1 $, 132 mm. (from eye to telson, rostrum broken). St. 100C. 4. x. 26 (day). West of Cape Town, 2500 (-0) m., 1 juv. 71 mm. St. 101. 15. x. 26 (night). West of Cape Town, 2 hauls: (i) 350-400 (-0) m., 1 juv. <$, 80 mm. (eye to telson) 1 juv. $, 73 mm., 1 2 Juv- St. 395. 13. v. 30 (day). North-east of South Georgia, 1600-1500 m., 1 adult 9, 37 mm. St. 679. 29. iv. 31 (night). East of Rio de Janeiro, 2000-1500 m., 1 adult 9, 35 mm- 1 Fage (footnote on p. 60) noted that Tattersall (1939, p. 228) had in error given the northern limit of this species as the east of Greenland based on a record of Stephensen. This record was in fact of E. unguiculata. Unfortunately in Tattersall and Tattersall (1951, p. 112) I repeated this error. SYSTEMATIC REPORT 55 St. 700. 18. v. 31 (day). North-east of Cape Verde Is., 2025-0 m., 1 imm. 2 $? (1 ovig.), 23 imm., largest adult 15 mm. St. WS 233. 5. vii. 28 (day). North-east of Falkland Is., 185-175 m., 1 $, 12 mm. St. WS 234. 5 vii. 28 (night). 195-207 m, 2 $£, 1 $, 36 imm. (largest adult 12 mm.). St. WS 236. 6. vii. 28 (dusk to night). North of Falkland Is., 272-300 m., 2 S3, larger 12-2 mm., 7 $$, largest 13-5 mm. St. WS 239. 15. vii. 28 (night). West of Falkland Is., 196-193 m., 1 $, 12 mm. St. WS 244. 18. vii. 28 (day). West of Falkland Is., 253-247 m., 2 <$<$, 2 ?$, 2 imm., largest adult 12 mm. St. WS 245. 8. vii. 28 (night). South-west of Falkland Is., 304-290 m., 1 damaged $ probably about 14 mm. St. WS 748. 16. ix. 31 (night). Magellan Strait, 30o(-o) m., 4 <$£, 11-2 mm.; 3 juv. $$ about 10 mm.; 3 $$, 12-8 mm.; 7 juv. $$ up to 10 mm. St. WS 749. 18. ix. 31 (day). Magellan Strait, 4o(-o) m., 2 fragments. . x. 31. (day). North of Falkland Is., 291-298 m., 1