838 PROTOZOOLOGY 



K. polyporum E. (Fig. 356, b). 120-200/* long; commensal on 

 Hydra. 



Genus Keronopsis Penard. Two ventral rows of cirri reaching 

 frontal field; caudals variable; macro nucleus usually in several 

 (rarely 2) parts; fresh or salt water. Numerous species. 



K. rubra (Ehrenberg) (Fig. 356, c). Reddish; 200-300/* long; salt 

 water. 



Genus Epiclintes Stein. Elongate; spoon-shaped; flattened ven- 

 tral surface with more than 2 rows of cirri; 2 marginal rows; frontals 

 undifferentiated; anals; no caudals; salt or fresh water. A few species. 



E. pluvialis Smith (Fig. 356, d). About 375m long; fresh water. 



Genus Holosticha Wrzesniowski. Three frontals along anterior 

 margin; 2 ventral and 2 marginal rows of cirri; anals; fresh or salt 

 water. Numerous species. 



H. vernalis Stokes (Fig. 356, e). 7 anals; about 180/z long; shallow 

 pools with algae. 



H. hymenophora S. (Fig. 356,/). 5 anals; 2 contractile vacuoles; 

 160-200/1 long; shallow pools. 



Genus Paraholosticha Kahl. Elongate-oval; flexible; ventral cirri 

 in 2 parallel oblique rows; with a row of stiff cirri along frontal mar- 

 gin, posterior to it 2 short rows of cirri; marginals continuous or 

 interrupted at posterior border; fresh water. 



P. herbicola K. (Fig. 356, g). 150-190/t long; fresh water among 

 algae. 



Genus Trichotaxis Stokes. Similar to Holosticha; but with 3 rows 

 of ventral cirri; fresh or salt water. 



T. stagnatilis S. (Fig. 356, h). About 160/t long; ellipsoid; in fresh 

 water among decaying vegetation. 



Genus Balladyna Kowalewski. Ellipsoid; frontals not well de- 

 veloped or lacking; 1 ventral and 2 marginal rows of cirri; long 

 dorsal and lateral stiff cirri; fresh water. 



B. elongata Roux (Fig. 356, i). 32-35/t by 11-12/*; fresh water 

 among plants and detritus. 



Genus Pleurotricha Stein. Oblong to ellipsoid; marginals continu- 

 ous; 8 frontals; 3-4 ventrals; 7 anals of which 2 are more posterior; 

 2 rows of ventral cirri; between ventrals and marginals 1-3 rows of 

 few coarse cilia; fresh water. 



P. lanceolata (Ehrenberg) (Fig. 356, j). 100-165/* long; 2 macro- 

 and 2 micro-nuclei. Manwell (1928) studied its conjugation, division, 

 encystment and nuclear variation. Encystment (Penn, 1935). 



Genus Gastrostyla Engelmann. Frontals distributed except 3 along 

 the frontal margin; ventrals irregular; 5 anals; macronucleus divided 



