498 PROTOZOOLOGY 



highly flattened; anterior end elevated at one side where cyto- 

 stome and cytopharynx with 10 rods are located. 



Genus Enchelydium Kahl. Somewhat similar to Spathidium; 

 but oral ridge forms a swollen ring with trichocysts, which is 

 circular or elongated in cross-section; when swimming, the or- 

 ganisms appear as if cytostome is opened; with dorsal bristle; 

 fresh water. 



E.fusidens K. (Fig. 229, g). Cylindrical, contractile; ciUa dense 

 and rather long; macronucleus reniform, often appears as com- 

 posed of 2 spherical parts; contractile vacuole terminal; oral ring 

 with spindle-like trichocysts; food vacuoles not seen; extended 

 body llO^i long; contracted 75//; sapropelic. 



Genus Homalozoon Stokes. Elongate; cilia only on flattened 

 right side; left side swollen or keeled; fresh water. 



H. vermiculare (S.) (Fig. 229, h). Extended body 450-850^ 

 long; vermiform; numerous macronu clear parts in band form; 

 contractile vacuoles about 30 or more in a row; standing pond 

 water. 



Genus Cranotheridium Schewiakoff. Spathidium-like organ- 

 isms; anterior end obliquely truncate, near the extended side of 

 which are located the cytostome, and cytopharynx surrounded by 

 a group of trichites or trichocysts ; fresh water. 



C. taeniatum S. (Fig. 229, i). Anterior end flattened; with a 

 group of trichites; macronucleus long band-form; with many 

 micronuclei; contractile vacuole terminal; ciliation and striation 

 close; colorless; movement slow; about 170/x long; fresh water. 



Genus Penardiella Kahl. Ellipsoid, somewhat compressed; oral 

 ridge slightly oblique; from this a girdle with trichocysts encircles 

 body; fresh water. 



P. crassa (Penard) (Fig. 229, j). Elongate elhpsoid, flattened; 

 trichocysts in posterior portion of girdle are longer and those in 

 the dorsal region are fewer in number and shorter; macronucleus 

 sausage-form; contractile vacuole posterior, in front of the girdle; 

 body lOOju by 50/^; sapropeHc. 



Genus Perispira Stein. Ovoid or cylindrical; oral ridge turns 

 down right-spirally to posterior end. 



P. strephosoma Stokes (Fig. 229, k). Oval to cylindrical; about 

 85/i long; standing water, with sphagnum. 



Genus Legendrea Faure-Fremiet. Ellipsoid or ovoid; a periph- 

 eral zone with small tentacular processes bearing trichocysts. 



