PARASITIC ISOPODS 393 



Bopyridae 

 Bo]jyriens Jomens 



Phryxiens 

 Entoniscidae 



Crj'ptoniscidsB 



Cabiropsidas 



Cyproniscidas 



Microniscidae 

 Microniscidte parasitic on Copepoda. 



Cyproniscidse 



Dajidae 



Cabiropsidas 



Cryptoniscidae 



Entoniscidae 



Ecpyridae 



Ostracoda. 



Schizopoda. 



Isopoda and Amphipoda. 



Cirripedia (chietiy 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 



