DESCRIPTION OF SPECIES 33i 



St. WS 820: 52° 53' 15" S, 61° 51' W, 351-367 m. 



St. WS 821 : 52° 55' 45" S, 60° 55' W, 461-468 m.; i <J, several damaged specimens. 



St. WS 839: 53° 30' 15" S, 63° 29' W, 403-434 m.; I ? (non-b.), 5 immature specimens. 



Diagnostic characters. The specimens in the collection are smaller than those 

 taken by the ' Challenger '. The actual body length of both the largest male and female 

 is 26 mm. ; but if the length of the seventh coxal plates is included this is increased to 

 37*5 mm. in the former, and 33 mm. in the latter, the difference in length being due to 

 the greater length of the coxal plates of the male. As in most species the male is pro- 

 portionately broader than the female and measures 33 mm. as compared with 28 mm., 

 the width of the female. 



The head is broader than long, broadest anteriorly, with a small rostrum behind 

 which a transverse ridge extends laterally to the margin of the cephalosome ; im- 

 mediately behind this is a fairly deep groove. The area between the eyes is convex, and 

 extending across this area, not far behind the anterior margins of the eyes, is a transverse 

 row of four spines, the inner ones of which are the smaller. The posterior margin of the 

 head is indented and forms three projections, the lateral of which are somewhat tri- 

 angular in shape ; the central one is elongated transversely and is oval in shape. Unlike 

 other deep-sea forms the eyes are large, being both long and broad ; they are reniform 

 in shape but not deeply pigmented, the colour being bluish-black. According to Beddard 

 (18846, p. 26) the minute structure resembles that of the eyes of S. bromleyana, 

 Suhm, but is a little less degenerate. 



On the lateral portion of the second thoracic somite is a transverse ridge extending 

 from about the middle of its inner margin to the lateral margin. The posterior margin of 

 this portion is curved forwards, then backwards, so that it does not extend back as far 

 as the middle portion of the segment. Each of the third to seventh thoracic somites has 

 its posterior margin produced in the middle dorsal line to form a spiniform process; 

 those of the third and fourth somites are larger than those of the other somites. The 

 third and fourth somites are sub-equal, the fifth a little longer, and the sixth and seventh 

 each a little shorter than the third. The coxal plates are long, narrow and spiniform, 

 increasing in length from before backwards ; those of the seventh thoracic somite extend 

 backwards for some distance beyond the extremity of the terminal segment, and in the 

 largest male in the collection reach a length of 20 mm. and extend backwards in a 

 direction almost parallel with the long axis of the body. The coxal plates of the third, 

 fourth and fifth somites are separated from them by sutures. 



The three free abdominal segments each possess a small median dorsal spiniform 

 process on the posterior border; the pleural plates of the second segment are long, 

 extending backwards for some distance beyond the end of the terminal segment ; those 

 of the third segment are short, hardly extending beyond the anterior margin of the 

 terminal segment. The terminal segment is slightly broader than long, roughly hexa- 

 gonal in outline. It has a slight median dorsal keel the length of which is divided into 

 three approximately equal lengths by two spines, the anterior one of which is the larger. 

 On either side of the posterior spine, connected to it by a curved ridge, is a small lateral 



