312 DISCOVERY REPORTS 



82-81 m.; I 3. St. WS 220: 47° 56' S, 62° 38' W, 108-104 m.; 2 immature. St. WS 222: 48° 23' S, 

 65° 00' W, 100-106 m.; I ? (b.), 3 immature. St. WS 787: 48° 44' S, 65° 24' 30" W, 106-iiom.; 2 ?? (b.), 

 a number immature. St. WS 796: 47° 49' 37" S, 63° 42' 30" W, 106-113 m.; i (J, 2 ?? (b.), 3 immature. 

 St. WS 797: 47° 45' 36" S, 64° 20' W, 115-111 m.; 2 cJc? (young). St. WS 808: 48° 28' 15" S, 65° 42' W, 

 109-107 m.; I cJ, II ?? (b.), a number immature. St. WS 811 : 51° 24' 30" S, 67° 53' W, 96-98 m.; 

 I $ (b.). St. WS813: 51° 35' 15" S, 67° 16' 15" W, 106 m.; icJ. St.WS8i4: 51° 45' 15" S, 66° 40' W, 

 Iii-ii8m.; 1 ? (non-b.). St. WS 815: 51° 51' 45" S, 65° 44' W, 132-162 m.; i immature specimen. 



Diagnostic characters. The body (Plate XIV, fig. 3) is pear-shaped owing to the 

 comparatively long terminal segment, and to the fact that the sixth and seventh thoracic 

 somites with their coxal plates are narrower than the preceding ones : the colour of the 

 body is a uniform pale brown. The largest male in this collection measures 31 mm. 

 in length and 24 mm. in greatest breadth, and the largest female 22 mm. in length 

 and 17 mm. in breadth. 



The head is sHghtly broader than long, broadest anteriorly, with a median rostrum 

 behind which a transverse ridge extends laterally to the sides of the cephalosome. The 

 eyes are reniform in shape, small but prominent, situated on raised areas placed rather 

 near together. The median portion of the head, behind but between the eyes, is slightly 

 raised and produced posteriorly into a small median spiniform process. 



The dorsal surface of the body is convex with a median carina which in the fourth 

 and fifth thoracic somites and in the three abdominal segments is produced backwards 

 as a small spiniform process. The coxal plates of each of the first three thoracic somites 

 are separated from their respective somites by sutures. The sixth and seventh somites 

 are narrow and together equal to the fifth ; the coxal plates of the seventh do not extend 

 backwards as far as the middle of the terminal segment. The pleural plates of the second 

 and third abdominal segments are short, not extending beyond the anterior margin of 

 the terminal segment ; those of the third are shghtly the longer. 



The terminal segment is roughly five-sided with a rather pointed posterior extremity. 

 On its dorsal surface are a median and two lateral carinae ; the latter are curved and 

 follow the lateral margin of the segment, but at some distance from it, and each ends in 

 a short spiniform process just anterior to the point of articulation of the uropod. The 

 median carina is found in the anterior part of the segment and also towards its posterior 

 extremity, the middle part being obsolete. 



Remarks. Beddard (1884 b, p. 37) describes a patch of plumose setae on the sternum 

 of each of the last three thoracic somites as a sexual character pecuhar to the males, and 

 mentions that a small tuft may also be found on some of the others. This patch is 

 present, however, on each of the sterna of the third to the seventh somites, that of the 

 fourth measuring in a large specimen as much as 4 mm. in width. The patch is absent 

 from the sterna of youiig males, apparently appearing along with certain other characters 

 when the final moult to the adult stage is reached. 



The appendages of this species have already been described, but some further ob- 

 servations are noted here. The mouth-parts are of the typical form, that of the cutting 

 edges of the mandibles is shown in Fig. 12 a. The outer lobe of the maxillula bears on 

 its truncate distal extremity nine simple spines and one pectinate seta having a bifid 



