E U CI LI A TA , HOW TRICHIDA 



349 



Prorodon griseus Claparede and Lachmann (Fig. 149, i). 

 Body oblong, about 50 to 70 microns long. Fresh water. 



Genus Ichthyophthirius Fouquet. Body oval. Ciliation uni- 

 form; pellicle longitudinally striated. Cytostome at or near the 

 anterior end, followed by a short cytopharynx with cilia. A 

 single horseshoe-shaped macronucleus and a small micronucleus. 

 Multiplication by binary fission during the actively motile 



Fig. 150 Ichthyophthirius multifiliis. a, free-swimming Individual (X 75 after 

 Biitschli); b-e, development within cyst; f, a young individual (X400 after 

 Fouquet); g, section through fin of a carp showing numerous parasites (XlO); 

 h, a catfish, Ameiurus albidus, heavily infected by the parasites (after Stiles). 



