834 PROTOZOOLOGY 



stome 1/3 the body length; frontals numerous, about 22 in addition 

 to 2 at anterior margin; ventrals small and numerous in 3 oblique 

 rows; no anals; marginals uninterrupted; contractile vacuole a long 

 canal near left border; fresh water. One species. 



E. brachytona S. (Fig. 354, h). 170-220/* long. 



Genus Gonostomum Sterki (Plagiotricha Kent). Flexible; 8 or 

 more frontals; 1-2 oblique ventral rows of short cirri; 4 or 5 anals; 2 

 marginal rows; fresh water. 



G. strenuum (Engelmann) (Fig. 354, i). Elongate; with caudal 

 bristles; about 150/t long; fresh water. 



Genus Hemicycliostyla Stokes. Elongate oval; flexible; ends 

 rounded; 20 or more frontals, arranged in 2 semicircular rows; adoral 

 row begins near center on right side of peristomal field; ventral sur- 

 face entirely covered with fine cilia; no anals; one or more contractile 

 vacuoles ; nucleus distributed ; fresh water. 



H. sphagni S. (Fig. 354, j). About 400-500/* long; marsh water 

 with sphagnum. 



Genus Hypotrichidium Ilowaisky. Two ventral and marginal rows 

 of cirri spirally arranged; peristome large, extends 1/2 the body 

 length, with a large undulating membrane; 2 macro- and micro-nu- 

 clei; contractile vacuole anterior-left; fresh water. 



H. conicum I. (Fig. 355, a). 90-1 50/* long. 



Genus Cladotricha Gajevskaja. Elongate band-form; anterior 

 end rounded, posterior end rounded or attenuated; frontals only 2 

 featherly cirri; macronucleus spheroidal; micronucleus; without con- 

 tractile vacuole; salt water, with 5-20 per cent salt content. One 

 species. 



C. koltzowii G. (Fig. 354, k, I). Band-form up to about 200/* long; 

 posteriorly attenuated forms up to about 100/* long. 



Genus Psilotricha Stein. Oval to ellipsoid; frontals and anals un- 

 differentiated; ventrals and marginals long cirri, few; ventrals in 2 

 rows and a rudimentary row toward left; with or without zoochlo- 

 rellae; fresh water. A few species. 



P. acuminata S. (Fig. 355, 6). 80-100/* long. 



Genus Kahlia Horvath. Frontal margin with 3-4 strong cirri; 

 5-8 ventral longitudinal rows ; marginals ; sapropelic in fresh water. 



K. acrobates H. (Fig. 355, c). 100-200/x long; soil infusion. 



Genus Uroleptus Ehrenberg. Elongate body drawn out into a tail- 

 like portion; 3 frontals; 2-4 rows of ventral cirri; marginals; no 

 anals; sometimes rose- or violet-colored; fresh or salt water. Many 

 species. 



U. limnetis Stokes (Fig. 355, d). About 200/x long; fresh water 

 among vegetation. 



