284 DISCOVERY REPORTS 



of the type usually found on this limb — there are eight spines in each row ; the dactylus 

 ends distally in a strong spine, arising just behind which are two other spines and three 

 short setae; its inner margin appears to be raised into a number of minute papillae. 

 With the exception of the merus and dactylus, the other joints of the 4-7 appendages 

 are fringed with strong setae, many of which are of the type shown in Fig. 3 d, whilst 

 some, at the distal ends of the joints, bear much stronger pectinations. 



The first three pairs of pleopods are of the usual type ; the protopodite of each is 

 somewhat triangular, with the prolonged angle bearing three plumose setae on the first 

 and two on each of the second and third pleopods : long delicate hairs are present around 

 the margins of the protopodite and also fringe the anterior margins of both the exo- 

 podite and endopodite. The suture of the exopod of the fourth pleopod is oblique and 

 towards the distal end ; both margins of the exopod are fringed with hairs, those of the 

 inner margin are replaced towards the distal end by plumose setae, and a group of these 

 setae surround the distal extremity ; the ventral surface of the exopod is covered with 

 long scattered setae which increase in size and number distally; the endopod has a 

 rounded distal extremity and bears no setae. 



The uropoda have already been described by Caiman (1920, pp. 300, 304, fig. 3). 

 Each consists of a protopodite which is prolonged into an acute point ; the exopod is 

 small and spiniform; the endopod is wanting. 



Distribution. The species has not been recorded since Caiman described it; the 

 present specimens come from the type locality. Deception Island, South Shetlands. 



2. Serolis latifrons, White. 



S. latifrons. White, 1847, p. 106; Miers, 1875, p. 74; 1876, p. 116; Smith, 1876, p. 63; 1879, p. 204; 

 Studer, 1879, p. 26 ; Beddard, 1 8846, p. 44, pi. ii, figs. 1-4 ; Vanhoffen, 1914, p. 5 18 ; Caiman, 1920, p. 299. 



Diagnostic characters. The largest specimen in the Challenger collection is a female 

 32mm. in length and 24 mm. in greatest breadth; the males are proportionately 

 broader than the females, the largest measuring 28 mm. in length and 24 mm. in 

 breadth : the body is oval in shape with an almost smooth dorsal surface. 



In this species, as in S. beddardi, Caiman, minute lateral portions of the tergum of 

 the eighth thoracic somite are present, and separated from them by sutures are small 

 coxal plates . The coxal plates of the remaining free thoracic somites are separated from 

 their respective somites by sutures ; they are closely applied together and those of the 

 seventh somite do not extend backwards as far as the bases of the uropoda. 



The terminal segment is almost triangular in shape, its anterior margin extends 

 laterally beyond the pleural plates of the second and third abdominal segments, which 

 are short ; near the antero-lateral margin, on either side, is a notch into which the base 

 of the protopodite of the uropod fits. A median and a pair of lateral sub-marginal ridges 

 are present on the dorsal surface. 



The protopodite of the uropod is produced distally as an acute prolongation ; the 

 exopod is reduced and spiniform and the endopod is absent. 



Distribution. Off Kerguelen. 



