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



First antennae long, with last joint of peduncle nearly as long 

 as preceding one; flagellum shorter than peduncle. Second 

 antennae extending but little beyond penultimate joint of peduncle 

 of first; last joint of peduncle longer than the preceding one; 

 flagellum biarticulate and shorter than last joint of peduncle. 



First gnathopods with propodus having palm nearly straight 

 and extending to proximal end of joint where it is defined by a 

 stout prehensile spine. Second gnathopods with basal joint 

 usually slightly dentate in front and produced below into an 

 acute lobe ; ischium and merus each with an acute inferior 

 process ; propodus with a triangular tooth at upper end of palm 

 and a narrow tooth below the middle separated from a triangular 

 eminence below by a narrow sinus. 



Third, fourth, and fifth pereiopods increasing in size poste- 

 riorly. 



Gills oval, elongated. 



Abdomen with two pairs of appendages in both sexes ; the 

 first pair of which are biarticulate. 



Length 16 mm. 



Distribution: Siberia; Greenland; Labrador; Eastport, 

 Maine; Narragansett Bay; Woods Hole, Massachusetts; Long 

 Island Sound; off Sea Flower Reef. 



The development of spines on the body is very variable ; they 

 may be reduced to small tubercles or entirely absent. 



Caprella Lamarck. 



Body more or less slender, being as a rule much more 

 elongated in the male than female. 



First antennae elongated. Second antennae generally densely 

 setose below, flagellum biarticulate. 



Mandibles without palp. Maxillipeds with outer plate 

 scarcely larger than inner one ; palp very strong. 



First gnathopods of usual structure. Second pair strongly 

 developed. First two pairs of pereiopods entirely wanting; three 

 posterior pairs of similar form, generally strongly built and sub- 

 chelate. Gills present only on the third and fourth thoracic 

 segments. 



Abdomen in female without distinctly defined appendages ; in 

 male with a pair of biarticulate limbs in front. 



