DESCRIPTION OF SPECIES 349 



third. The appendix mascuHna on the second pleopod reaches about two-thirds of the 

 way towards the apex of the terminal segment. The suture of the exopod of the fourth 

 pleopod is slightly oblique and the outer border is fringed with plumose setae; the 

 endopod is not divided by a suture, and does not bear setae ; a suture extends for a short 

 distance across the exopod of the fifth pleopod. 



Unfortunately the right uropod is damaged, but if the left is complete, as it appears 

 to be (Fig. 19 d), it resembles that of S. beddardi, Caiman, and S. latifrons, White, in 

 the absence of the endopod. It differs from them, however, in having the protopodite 

 and its produced spine short, not produced into a long spiniform process. The exopod 

 is very small, oval in shape and 1-5 mm. in length, with its outer margin and rounded 

 end notched and bearing a few delicate setae. 



This species most closely resembles S. boiivieri, Richardson, but can be readily dis- 

 tinguished from it by the fact that in the latter the outer edges of the coxal and pleural 

 plates and also the margins of the terminal segment are greatly thickened, and that the 

 posterior region of the head is raised into two prominent tubercles which meet in the 

 middle line. In the latter species, also, the eyes are well developed and contain black 

 pigment, whereas in the former the eyes are small and very narrow. 



Distribution. 53° 48' 00" S, 35° 37' 30" W, north-east of South Georgia. 



31. Serolis bouvieri, Richardson (Fig. 20). 



S.bouvieri, Richardson, 1906 «, p. 7, text-figs. 12, 13, pi. i, fig. i; Nordenstam, 1933, pp. 89-90, 

 text-figs. 5 a, 11 a. 

 Occurrence. St. 181 : Palmer Archipelago, 160-335 "^-S 2 immature specimens. 



St. 190: Palmer Archipelago, 93-130 m.; i adult cJ and i ? (non-b.). 



St. 190: Palmer Archipelago, 315 m.; i ? (non-b.). 



St. 195: South Shetlands, 391 m.; i adult cJ, 16 immature specimens. 



Diagnostic characters. The body is oval, longer than broad, with the whole sur- 

 face covered with scattered shallow pits. On either side of the long rostrum the head is 

 excavated for the reception of the antennules, and the posterior region is raised into two 

 prominent tubercles which meet in the middle line. The eyes are placed one on the 

 outer side of each tubercle ; they are reniform in shape and contain black pigment. 



The postero-lateral angles of the coxal plates of the thoracic somites are produced 

 backwards and have their distal ends rounded and thickened, a thickening which gives 

 the species a very characteristic appearance. The terga of the first three free thoracic 

 somites are separated by sutures from their respective coxal plates ; the terga of the 

 sixth and seventh thoracic somites are fused with each other and with the tergum of the 

 first abdominal segment in the mid-dorsal line. 



The terminal segment is a little broader than long, with its greatest width towards 

 the middle of the segment ; it narrows posteriorly to about a third of its width. The 

 rounded postero-lateral angles are thickened and are produced for about 1-5 mm. 

 beyond the central tip of the segment, the median dorsal carina of which extends as a 

 short projection. In some specimens a small lateral carina is present, one on either side 

 of the median; this is less noticeable in large specimens. The uropoda are very small, 



DVII 13 



