I4 6 DISCOVERY REPORTS 



St. 123. 15. xii. 26 (day). Mouth of Cumberland Bay, 230-250 m., 54 $$, largest 16-2 mm., 70 ?$, largest 



i6-4mm. 

 St. 140. 23. xii. 26 (day). Cumberland Bay, 122-136 m., 4 badly damaged. 

 St. 142. 30. xii. 26 (day). East Cumberland Bay, 88-273 m -> 3 2 <$& 2 ° ??> 19 J uv - 

 St. 144. 5. i. 27 (day). Off South Georgia, 155-178 m., fragments. 



St. 148. 9. i. 27 (day). Off Cape Saunders, South Georgia, 132-148 m., 5 adult $$, 16-2 mm. 

 St. 154. 18. i. 27 (day). Off South Georgia, 60-160 m., 50 <?<J, 54 ??> largest 17 mm., over 200 juv. Types. 

 St. 190. 24. iii. 27 (day). Palmer Archipelago, 93-126 m., fragments (doubtful). 

 St. WS 219. 3. vi. 28 (day). North of Falkland Is., 116-114 m., 1 $ (doubtful). 

 St. MS 20. 9. iv. 25 (day). East Cumberland Bay, 200-160 m., 1 imm. $, n-a mm. 



St. MS 27. 29. iv. 25 (day). East Cumberland Bay, 160-120 m., 2 S<$, larger 14 mm., 1 adult ?, 14 mm., 1 juv. 

 St. MS 68. 2. iii. 26 (day). Cumberland Bay, 220-247 m -- 7°> a11 imm - 

 St. MS 71. 9. iii. 26 (day). East Cumberland Bay, 110-60 m., large numbers of fragments. 



Description. Carapace very short anteriorly, with the short acutely pointed rostral plate produced 

 forward between the widely diverging eyes (Fig. 32 A); lateral margins of rostrum markedly concave 

 and more or less uptilted. In many specimens the anterior portion of the rostrum is bent downward 

 between the eyes and in dorsal view appears to be blunter and shorter than it really is. Antenna! 

 peduncle unusually long, extending slightly beyond the distal margin of the antennular peduncle; 

 scale small and narrowly oval, five times as long as broad; upper dorsal spine on the sympod at the 

 base of the scale short and thick and rather blunt, ventral spine long and sharp (Fig. 32A, B). 

 Eyes small, set widely apart and diverging, eyestalk rather long, cornea not wider than eyestalk and 

 occupying the distal end of the organ, not extending along the outer lateral margin of eyestalk 

 (Fig. 3 2 A). Pigment pale yellow to gold, very rarely dark in preserved specimens. Mandibles strong 

 with well-developed lacinia mobilis and unusually strong spine row; palp slender (Fig. 32 C). First and 

 second thoracic appendages somewhat long and slender (Fig. 32 D, E). Endopods of remaining thoracic 

 appendages with the carpo-propodus composed of seven (occasionally eight) sub-segments. In some 

 specimens the eighth has only six sub-segments; nail well developed (Fig. 32 F). Male genital organ 

 robust and somewhat thickened distally, extending forward to the first thoracic somite in largest 

 specimens. Pleopods rather unusually long for the genus (Fig. 32 G). Uropods, endopods extending 

 only slightly beyond the apex of telson; inner margin armed with 16-17 nne > irregularly spaced spines 

 extending along the distal three-fourths of the margin, smaller and more crowded proximally 

 (Fig. 32 H). Telson more than twice as long as broad at the base; lateral margins armed at the base 

 with 5-6 strong spines succeeded by 4-5 widely spaced very tiny spines, which are absent in smaller 

 animals, and then by a close row of spines arranged in series. The long spines of this series may be very 

 long and slender and the small spines in the spaces between them are particularly small and not 

 graduated ; cleft shallow and widely open, one-twelfth of the length of the telson in depth ; armed with 

 about 13-14 small even teeth on each side (Fig. 32J). 



Length of adults of both sexes, 17 mm., but females of 13 mm. may have very large oostegites and 

 one of 13 mm. from station 42 was ovigerous. 



Remarks. M. microps can at once be recognized by the small golden eyes with the cornea small and 

 confined to the distal end of the organ. In this respect it differs sharply from nearly all the other 

 species of the genus in which the eyes are large and the cornea extends over the lateral portion of the 

 organ almost to its base. The shallow, widely open cleft of the telson also affords a ready means of 

 recognizing the species. 



Distribution. All the certain captures of this species were made in or off the mouth of Cumber- 

 land Bay, South Georgia. All were taken during hours of daylight during the southern summer, in 

 depths of 60-273 m ' 





