ISOPODS OF NORTH AMERICA. 



515 



the edges of which are formed of a considerable and dense quantity of 

 long dictations, some of which are subdivided into secondary digita- 

 tions; these prolongations are especially developed on the first segments 

 of the abdomen; they decrease in length on the last segments. The 



FK;. 562. GRAPSICEPON EDWARDSI (AFTER "BONNIER), a, VENTRAL VIEW OF ABDOMEN. 6, INFE. 



RIOR PART OF HEAD WITH RIGHT MAXILLIPED. C, BOTH ANTENN.fi. d, RIGHT LEG OF FOURTH 



PAIR (FEMALE), e, ROSTRUM WITH RIGHT MANDIBLE IN SITU. /, PARASITE IN BRANCHIAL CAVITY 

 OF HOST, g, LAST THORACIC SEGMENTS (DORSAL VIEW), h, EXTREMITIES OF THE MANDIBLES. 



outer branches of the pleopods present exactly the same form as the 

 pleural parts, but they increase in length in an inverse order, from 

 the first to the fifth segment, where they are the longest; the inner 

 branches are reduced to large tubercles with irregular surface, fixed 



