370 CRUSTACEA 



G. fasciatus Say (Fig. 583). First and second antennae of about 

 the same length; length 15 mm.; color whitish: common in fresh- water 

 ponds and streams, it and Hyalella dentata being the common fresh-water 

 amphipods in the eastern states. 



2. CARINOGAMMARUS Stebbing. Telson deeply cleft; last 3 abdom- 

 inal segments with bunches of small hairs and first 3 each with a dorsal 

 backwards projecting spine: about 9 species. 



0. mucronatus (Say) (Fig. 584). Antennae of the same length; 

 length 15 mm.; color greenish: Cape Cod to Florida, common among 

 algae and in brackish water. 



Fig. 584 Fig. 585 



Fig. 584 Cwinogammarus mucronatus (Paulmeier). Fig. 585 Elasmopus Icevis 



(Paulmeier). 



3. ELASMOPUS Costa. First antennae twice as long as the second; 

 first 3 abdominal segments very large, last 3 small and bent beneath 

 them: about 9 species. 



E. laevis (S. I. Smith) (Fig. 585). Last 3 pairs of abdominal ap- 

 pendages short and thick ; length 10 mm. ; color brownish ; first gnathopods 

 small, second large: Cape Cod to New Jersey, under rocks and among 

 seaweeds near low-tide mark. 



FAMILY 6. PHOTIDAE. 



First antennae with or without a small secondary flagellum and longer 

 than the second; mandible with a long palp; second gnathopods larger 

 than the first: 10 genera and about 40 species. 



LEPTOCHEIEUS Zaddach (Ptilocheirus Stimpson). Terminal pleopods 

 biramose ; both pairs of gnathopods large and chelate ; first antennae with 

 a minute secondary flagellum: 8 species. 



L. pingius Stim. Body thick, and variegated in color; length ,13 

 mm.: New Jersey to Labrador; common on muddy bottoms. 



