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



posterior part of lower margin produced into a rounded lobe. 

 First three abdominal segments with postero-lateral angles 

 evenly rounded and with margin above angle minutely crenulated ; 

 fourth abdominal segment with a rather deep dorsal depression 

 near the anterior end. 



Terminal uropods with styliform rami; inner ramus more 

 slender than outer and extending only as far as basal segment of 

 the latter. Telson tapering distally and cleft to beyond the middle. 



Color whitish. 



Length, 5 mm. 



Distribution : Arctic regions ; Norway ; Greenland ; Labrador ; 

 Woods Hole ; off Martha's Vineyard ; Long, Island Sound. 



This species has been referred recently to the genus Tryphosa 

 but it differs from the latter particularly in the position of the 

 mandibular palp which is behind the molar tubercle ; in the carpus 

 of the first gnathopod which is shorter than the propodus (in 

 Tryphosa the two joints are more nearly of the same length) 

 and in the propodus of the second gnathopod which is not pro- 

 duced beneath the dactyl in Tryphosa. 



STEGOCEPHALIM;. 



Head short. Fourth coxal plates large. 



First antennae with accessory flagellum uni- or biarticulate. 

 Second antenna: seldom much longer than first. 



Lower lip without inner lobes. Mandibles without molar 

 tubercle or palp. First maxillae with inner plate with numerous 

 setae. Second maxillae with inner plate very broad and setose, 

 outer narrow. 



Gnathopods not subchelate. Third pereiopods with basal joint 

 not expanded. 



Terminal uropods biramous. Telson small. 



Stegocephalus inflatus Kroyer. 



1891. Stegocephalus inflatus, G. O. Sars, Crust. Norway, 

 vol. i, p. 198, pi. 69. 



Body tumid and smooth. Rostrum prominent, deflexed, and 

 with a deep sinus below. 



Eyes wanting. First antennae with accessory flagellum having 

 second joint minute. 



Mandibles with palp wanting. 



