1908] BmdJcij. — Anipliipods of the Genus Corophium. 229 



Lentil 0.4 inch. Found among confervae, etc., in the salt marshes 

 on the shores of San Francisco Bay. ' ' 



In a subsequent paper Stimpson ('57a) repeats the descrip- 

 tion of C. spinlcornc and adds that of C. salmonis as follows: 



"In examining- anatomically a species of salmon from Puget 

 Sound, in the museum of the Smithsonian Institute, the stomach 

 was found to be filled with Amphipods, chiefly a species of Coro- 

 phium. The specimens Avere not in a very good state of preserva- 

 tion, but enough remained to show that although agreeing with 

 the preceding species (spinicorne) in most character, particular- 

 l.y in the spines of the antennae and the hairiness of the feet, 

 they are yet specifically distinct. The body is rather more elon- 

 gated and depressed than in spinicorne, the inferior antennae are 

 much longer, and the superior ones smaller. The color is reddish- 

 purple. " 



KEY TO THE SPECIES OF COEOPHIUM. 



This key includes all the species accepted by Stebbing ('06) 

 including those in the appendix, except C. maeoticum Sowinsky 

 ('98, Bull. Acad. St. Petersb., vol. 8, p. 362; pi. 1, figs. 1-5). 

 It is based on the synopsis given by Stebbing ( '06), but modified 

 so as to exclude secondary sexual characters, such especially as 

 are found in the antennae. 



1. Abdominal segments 4-6 distinct 2 



Abdominal segments 4-G fused 15 



2. Ramus of third uropod oval 3 



Ramus of third uropod parallel-sided 9 



3. Second antennae chelate 4 



Second antennae not chelate 5 



4. Abdominal segments 4-6 smooth C. chelicorne Sars. 



Abdominal segments 4-6 spinulose C. spinulosum Sars. 



5. Dactyl of second gnathopod simple, slender; propodus of first pe- 



raeopod slightly over one-third as broad as long; telson obtusely 



pointed C. volutator Pallas. 



Dactyl of second gnathopod toothed 6 



6. Dactyl of second gnathopod long and slender, four to seven times as 



long as greatest breadth, bearing 1 to 5 small recumbent teeth be- 

 sides a long apical tooth 7 



Dactyl of second gnathopod very stout, about as broad as long, with 

 three large recurved teeth, the third forming the apex of the 

 dactyl C. triaenonyx Stebbing. 



