PAKASITIC ISOPODS 393 



Bopyridas 

 Sopyriens loniens 



Phryxiens^ 

 Entoniscidce 



Cryptoniscidae 



Cabiropsidse 



CyproniscidEe 



Microniscidae 



Microniscidaj parasitic on Copepoda. 

 Cyproniscidas , Ostracoda. 



Dajidee 



Cabiropsidte 



Cryptoniscidse 



Entoniscidas 



Bopyridte 



Schizopoda. 



Isopoda and Amphipoda. 



Cirripedia (chiefly the parasitic). 



Brachyura. 



Brachyura and Macrura. 



The Epicaridea are all, strictly speaking, external para- 

 sites, although according to position on their host they may 

 be classified as abdominal, branchial, or visceral. In those 

 which inhabit the branchial chambers of other crustaceans, 

 the form of the female becomes obliquely ovate, the convex 

 side being on the right or the left, according as the animal 

 occupies the right or left side of its host. In some genera 

 (Kepon, Gyge, lone), a right-hand female has the marsu- 

 pial plates of the right side overlapping those of the left, 

 while the reverse is the case in a left-hand female. The 

 plates are so imbricated that the last of the five pairs is 



