HOLOTRICHA 771 



about 50ju long; Kellicott's (1885) form is more elongated; in fresh 

 water. 



Genus Histiobalantium Stokes. Ovoid; ventral side flattened; 

 ciliation uniform; long stiff cilia distributed over the body surface; 

 peristome deep; both anterior and posterior regions with a well- 

 developed membrane, connected with the undulating membrane; 

 macro nucleus in 2 parts; 1-2 micro nuclei; several contractile vacu- 

 oles distributed ; fresh water. 



H. natans (Claparede and Lachmann) (Fig. 328, c). 70-1 10/x long. 



H. semisetatum Noland (Fig. 328, d). Elongate ellipsoid; posterior 

 end bluntly rounded; macro nucleus spherical; longer cilia on pos- 

 terior half only; contractile vacuoles on dorsal side; 126-205/x long; 

 salt water; Florida (Noland, 1937). 



Genus Pleurocoptes Wallengren. Ovoid, dorsal side hemispher- 

 ical, ventral side flattened; peristome large, reaching the posterior 

 1/3; cyto pharynx indistinct; longer cilia along peristome; macro- 

 nucleus spherical; several micronuclei; contractile vacuole terminal; 

 ectocommensal. 



P. hydractiniae W. (Fig. 328, e). 60-70/x long; on Hydractinia 

 echinata. 



Family 4 Cohnilembidae Kahl 



Genus Cohnilembus Kahl (Lembus Cohn). Slender spindle-form; 

 flexible; peristome from anterior end to the middle of body or longer, 

 curved to right, with 2 membranes on right edge; a caudal cilium or a 

 few longer cilia at posterior end; macro nucleus oval, central; in salt 

 or fresh water, some parasitic. 



C. fusiformis (C.) (Fig. 328, /). Striation spiral; peristome about 

 1/6 the body length; a few cilia at posterior end; oval macronucleus 

 central; contractile vacuole posterior; about 60ju long; in fresh water. 



C. caeci Powers (Fig. 328, g). About 32-92/z long; in the intestine of 

 Tripneustes esculentus and other echinoids; Tortugas. 



Family 5 Philasteridae Kahl 



Genus Philaster Fabre-Domergue (Philasterides Kahl). Body 

 cylindrical; peristome about 1/3-2/5 the body length, broader near 

 cytostome and with a series of longer cilia; cytostome with a triangu- 

 lar membrane; cyto pharynx (?); ciliation uniform; a caudal cilium; 

 trichocysts; oval macronucleus with a micro nucleus, central; con- 

 tractile vacuole terminal or central; in salt or fresh water. 



P. digitiformis F-D. (Fig. 328, h). Anterior region bent dorsally; 

 contractile vacuole terminal; 100-150^ long; salt water. 



