l62 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



Antennae slender, subequal, peduncle long; flagellum of several 

 joints; no accessory flagellum; second antennae attached much 

 behind first; third joint of peduncle unusually elongated. 



Mandibles short and stout with palp much elongated and 

 having terminal joint lamellar and densely setose. Maxillipeds 

 with palps comparatively narrow. 



Gnathopods very unequal, the anterior ones small, with carpus 

 comparatively large and expanded posteriorly; propodus short 

 but broad. Second gnathopods in female considerably larger than 

 first and with carpus produced posteriorly; propodus expanded, 

 with palm well defined, in the male of enormous size and com- 

 plexly chelate, the carpus being extremely large and bearing 

 ventrally an acuminate thumb-like process; propodus narrower 

 than carpus and having palm imperfectly defined. Anterior 

 pereiopods with basal joints lamellarly expanded. 



Last pair of uropods with a single lamellarly unguiform 

 ramus. Telson short and broad with two densely spinous pro- 

 cesses above. 



Ericthonius rubricornis (Stimpson). 



1853. Cerapus rubricornis, Stimpson, Marine Invert. Grand 

 Manan, Smithson. Contrib. Knowl., vol. 6, p. 43, fig. 33. 



1880. Erichthonius difformis, Smith, Trans. Conn. Acad., 

 vol. 4, p. 278. 



Eyes nearly round. Interantennal lobes projecting strongly 

 forward. 



First antennae slightly longer than second, with second and 

 third peduncular joints subequal in length and not quite twice as 

 long as first joint; flagellum short. Second antennae with last 

 joint of peduncle a little longer than preceding one; flagellum 

 short and furnished with long setae on lower margin. 



First gnathopods with merus produced distally to a triangular 

 process ; carpus large, widening distally ; propodus smaller than 

 carpus and greatly constricted at base, two-thirds as broad as 

 long, palm slightly convex and finely serrated and passing gradu- 

 ally into posterior margin; dactyl strong, armed with a few 

 short spines. Second gnathopods in male very large, with carpus 

 produced below propodus into a large acute process ; propodus 

 oblong, with a prominence near the distal end of posterior margin ; 



