540 PROTOZOOLOGY 



Paramecium, the genus with only one species is mentioned here. 

 P. spiwiosa (Penard) (Fig. 244, g). Oval to cyhndrical; highly 

 plastic; cytoplasm reticulated; numerous contractile vacuoles; 

 150-320/x long; in fresh water. 



Family 9 Colpodidae Poche 



Genus Colpoda Mtiller. Reniform; flattened; right border semi- 

 circular; posterior half of left border often convex; oral funnel 

 in the middle of flattened ventral side, but toward left border 

 where depression occurs, which leads into peristome cavity and 

 gives rise dorsally to a diagonal groove; left edge of cytostome 

 bears a cross-striped ciliated area, but no protruding membrane 

 as in Bryo'phrya; macronucleus spherical or oval, central; con- 

 tractile vacuole terminal; in fresh water. Many species. 



C. cucullus M. (Fig. 247, a, b). About 80/x (50-120m) long; an- 

 terior keel with 8-10 indentations; macronucleus with a stellate 

 endosome; trichocysts rod-form; food vacuoles dark; in fresh 

 water with decaying plants and infusion. 



C. inflata (Stokes) (Fig. 247, c). 50-80/x long; anterior keel with 

 6-8 indentations; macronucleus similar to that of C. cucullus; 

 in fresh water in vegetation. 



C. calif ornica Kahl (Fig. 247, d). About 30/x long; highly flat- 

 tened; cytostome small; protrichocysts very granular; cilia deli- 

 cate, long, in a few rows; macronucleus with a stellate endosome; 

 in moss; California. 



C. steini Maupas. 25-45/i long; 5-6 preoral ridges; in fresh 

 water. Reynolds (1936) found that it adopts itself to various 

 organs of the land slug, Agriolimax agrestis. 



Genus Tillina Gruber. Similar to Colpoda in general appearance 

 and structure; but cytopharynx a long curved, ciliated tube; in 

 fresh water. 



T. magna G. (Fig. 247, e,f). 180-200m long (Gruber) ; up to 400m 

 long (Bresslau) ; macronucleus oval, with 6 micronuclei ; contrac- 

 tile vacuole terminal, with 6 long collecting canals; in stagnant 

 water and also coprozoic. 



Genus Bresslaua Kahl. General body form resembles Colpoda; 

 but cytopharynx large and occupies the entire anterior half. 



B. vorax K. (Fig. 247, g). 80-120)U long; in fresh water. 



Genus Bryophrya Kahl. Ovoid to ellipsoid; anterior end more 

 or less bent toward left side; cytostome median, about 1/3 from 



