88 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



First four coxal plates deeper than broad and about as deep 

 as their respective segments and increasing successively in depth. 



First and second gnathopods of similar form and nearly equal 

 size, the second being a trifle the larger, and with the lobe on the 

 posterior side of carpus longer and narrower than in first; propo- 

 dus ovate, palm very oblique with a row of stout spines on outer 

 side which begins a little beyond the middle of the palm. 



First two pairs of pereiopods with merus strongly produced 

 downward at anterior angle ; last three pereiopods with merus 

 strongly produced downward at posterior angle, that of last pair 

 being more dilated than in the preceding ones. 



First three abdominal segments more or less produced at 

 posterior end to form a keel, especially developed in older speci- 

 mens, and second, third, fourth, and sometimes also first de- 

 pressed in front. Postero-lateral angles of second and third seg- 

 ments with a small tooth. 



First uropods with outer ramus markedly shorter than inner 

 which is a little shorter than the peduncle, both margins of 

 peduncle and rami armed with numerous short spines ; second 

 uropods with peduncle relatively broader than that of first and 

 somewhat shorter than inner ramus, outer ramus much shorter 

 than inner; terminal uropods extending beyond the others, rami 

 flattened, lanceolate, subequal, much longer than peduncle with 

 both margins of each furnished with numerous spines and 

 plumose setas. 



Telson oblong, slightly tapering and rounded at tip. 



Length 13 mm. 



Distribution: Greenland, Labrador, Halifax, Arctic regions, 

 Norway, British Isles, Narragansett Bay (Judd), Vineyard 

 Sound (Smith), Woods Hole, Gloucester, Long Island Sound. 



The species is largely pelagic and is often taken in large 

 numbers on the surface at Woods Hole, especially in the winter. 



BATEID^. 

 Head strongly rostrate. First coxal plate rudimentary. 

 First antennas without accessory flagellum. 

 Mandibles with palp. 



First gnathopods degraded, without propodus or dactyl. 

 Telson cleft. 



