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



First antennas as long as head and first segment of thorax 

 together, extending well beyond the peduncle of second antennae ; 

 peduncle with joints becoming successively smaller; fiagellum 

 longer than peduncle and made up of about ten joints. Second 

 antennae with last joint of peduncle the longest ; fiagellum longer 

 than peduncle and made up of about a dozen segments. 



First gnathopods in the male with short, stout basal joint, 

 scarcely twice as long as wide; carpus triangular, with short, 

 posterior margin strongly convex and armed with many setae; 

 propodus subrectangular with front margin strongly convex, 

 about twice as long as wide, palm slightly oblique and convex ; 

 dactyl stout and curved. Second gnathopods very large; basal 

 joint stout and expanded below in front; merus bearing a tri- 

 angular process distally ; carpus very small and inconspicuous ; 

 propodus large and oval, palm oblique and convex, armed with a 

 row of short spine teeth, prehensile angle prominent but rounded. 



In the female the two pairs of gnathopods are of the same 

 form, but the second pair is slightly larger than the first and the 

 carpus of the first is relatively longer than that of the second; 

 propodus subrectangular with fascicle of spines at middle of 

 posterior margin, dactyl longer than palm. Pereiopods stout, and 

 provided with numerous spines and setas. Third to fifth pereio- 

 pods with basal joint expanded and hind margin smooth. Fourth 

 and fifth pairs with propodus armed with a spine at the middle 

 of the hind margin. 



Postero-lateral angle of third abdominal segment very slightly 

 produced, forming less than a right angle. 



First uropods extending beyond the others; rami short and 

 spinous on margins and apex. Terminal pair small, with ramus 

 much shorter than peduncle. 



Telson divided into two obtuse lobes. 



Length 6-8 mm. 



Distribution: Atlantic coast of Europe; Azores; Bermuda; 

 Noank, Connecticut, low water, Aug. 29, 1874, and Long Island 

 Sound. 



Hyalella Smith. 

 Similar to Hyde except that first maxillae have a smaller palp 

 not reaching the base of apical spines of outer plate. Second 



