536 



PROTOZOOLOGY 





Fig. 244. a, Plagiopyla nasuta, X340 (Kahl); b, P. minuta, X400 

 (Powers); c, Lechriopyla mystax, X340 (Lynch); d, Sonderia pharyn- 

 gea, X590 (Kirby); e, S. vorax, X310 (Kahl); f, Clathrostoma viminale, 

 X220 (Penard); g, Physalophrya spumosa, Xl60 (Penard). 



S. vorax Kahl (Fig. 244, e). Broadly ellipsoid; size variable, 

 70-180^1 long; ventral surface flattened; posterior border of peri- 

 stomal cavity extending anteriorly; in salt marsh; California 

 (Kirby). 



Family 7 Clathrostom.idae Kahl 



Genus Clathrostoma Penard. Ellipsoid; with an oval pit in 

 anterior half of the flattened ventral surface, in which occur 3-5 

 concentric rows of shorter cilia; cytostome a long slit located at 

 the bottom of this pit; with a basket composed of long fibrils on 

 the outer edge of pit; in fresh water. 



C. viminale P. (Fig. 244, /). Resembles a small Frontonia 

 leucas; macronucleus short sausage-form; 4 micronuclei in a com- 



