PARASITIC ISOPODS 393 



BopyridK 

 BopT/riens Joniens 



Phryxiens . 

 EntoniscidiB 



CryptonisoidsB 



CabiropsidjE 



CypronisoidK 



Microniscidaa 

 Microniscidse parasitic on Copepoda. 



Cyproniscidae 



Dajidas 



Cabiropsidffi 



CryptonisoidiE 



EntonisoidEe 



Bcpyridse 



Ostracoda. 



Sctiizopoda. 



Isopoda and Amphipoda. 



Cirripedia (chietiy the parasitic). 



Braohyura. 



Braohyura 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, Oyge, 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 



