22 RESEARCH IN PROTOZOOLOGY 



open to question. Victor- Jones (191 5) found specimens of K. 

 (poiyporum) pediculus both on the outer surface and in the 

 enteron of Hydra tnridis. He observed that when food became 

 scarce more of the ciliates passed into the interior. He suggests 

 that a symbiotic relationship exists between this ciHate and its 

 host, the former keeping the surface of the latter clean of dead 





Fig. 6. — IchthyophtJiiriiis multifiHis. a, vegetative stage: {cv) , contractile 

 vacuoles; (n), macronucleus ; o, cytostome. b, cyst (r) from which uninucle- 

 ate ciliates (/) are escaping. X 75. (From Hegner and Taliaferro, after 

 Fouquet.) 



epithelial cells and micro-organisms which might be harmful. It 

 is not unusual for the ciliates to leave their host temporarily and 

 crawl around in the immediate vicinity searching for food. They 

 are frequently found in company with Trichodiua pediculus. 



Description: Size, 65^ x I30;u; body kidney-shaped, flattened dorso- 

 ventrally; creep around on surface of hydras feeding on dead epithelial 

 cells of host and free-living micro-organisms. 



Order peritricha. 



(a) CycIocJiccfa spoiujilUc Jackson. 



Jackson (1875) described a new ciliate from the outer cortical 

 layer of the fresh-water sponge, Spongilla flivi'iatilis. It differs 

 from the related genera, Triclwdina and Urccohvia in that it pos- 

 sesses no anterior adoral groove and spiral of cilia and its posterior 

 setae form an erect fringe, the altitude of which is about twice that 

 of the body. He established a new generic name, Cyclochceta, for 



