CHALARASPIS ALATA. 183 



distinctly keeled. The i)c)stero-lateral part of the carapace at each side is some- 

 what produced backwards and rounded as in Eucopia. 



The eyes (fig. lb, o.) are small, a little compressed, seen from above (fig. la) 

 oblique-ovate, light reddish. — The antennular peduncles short and extremely 

 thick; second joint with an oblong, slender, moderately short process on the 

 outer side; third joint with the front margin projecting in an oblong, very acute 

 process above the insertion of the upper flagellum and a somewhat similar 

 process more downwards on the inner side of the joint; the upper flagellum 

 thin, with numerous joints and about as long as the peduncle; lower flagellum 

 very strong. — Last joint of the antennal peduncle with a small process on the 

 outer side just below the insertion of the squama; the squama itself is a thin 

 plate reaching somewhat beyond the end of the antennular peduncle, it is some- 

 what more than twice as long as broad (fig. Ic) with the inner margin very 

 convex and setose, the outer margin a little bent angularly near or a Httle beyond 

 the middle and its proximal part glabrous, the distal part serrate with 9-12 

 acute saw-teeth somewhat different in size. 



The five anterior abdominal segments somewhat thick, dorsally flatly 

 convex, and some among them even with a small, a little excavated dorsal 

 area; lateral plates of the anterior segments rounded, on fifth, and sometimes 

 on fourth, segment the postero-lateral angle is produced in a tiny or small, 

 acute tooth. Sixth segment about as long as the fifth, with two pairs of obliquely 

 transverse, somewhat short and shallow furrows; the two pairs of lateral teeth 

 very acute. The uropods (fig. 11) with the endopods slightly overreaching 

 the telson and a little longer than the exopod, which has the end truncate and 

 three or four faint serrations along the outer margin. Telson (fig. 11) very 

 oblong-triangular, scarcely three times as long as broad, above with a pair 

 of high, longitudinal, very feebly serrate keels a little from the lateral margins, 

 and the area between these keels excavated longitudinally; the distal half of 

 each lateral margin with 5 or 6 spines; the end of the telson truncate, but hairs 

 or spines wanting — perhaps lost? — in the specimens. 



Length of the largest specimen, a probably adult male, 35 mm. 



Remarks. — I do not entertain the slightest doubt that the species described 

 here is C. alata. And I think it very important that it has been possible to fill 

 the gap in our knowledge of the only hitherto imperfectly studied genus of the 

 small but highly interesting suborder Lophogastrida. 



Distribution. — The "Challenger" specimen was taken in the South Pacific: 

 "lat. 50° 1' S., long. 123° 4' E.; depth, 1800 fathoms." It is certainly a bathy- 

 pelagic form. 



