HYPOTRICHIDA 389 



Genus Uroleptus Ehrenberg. Body sometimes rose or violet 

 in color. Elongate to cylindrical. The anterior end rounded, 

 posterior end more or less drawn out. Three frontals; 4 or 

 5 rows of ventral cirri, but no posterior cirri. Peristome about 

 one-third the length of the body. Fresh or salt water. 



Uroleptus musculiis Ehrenberg (Fig. 166, h). Fresh water. 

 Body about 130 to 210 microns long. 



Genus Pleurotricha Stein. Body oblong with rounded ends. 

 Marginal rows of cilia continuous. Five anals. Ventral cilia in 

 two rows or somewhat irregular. Between the ventral and 

 marginal rows are 1 to 3 rows of coarse cilia. Peristome broad, 

 one-third the body length. Fresh water. 



Pleurotricha lanceolata (Ehrenberg) (Fig. 166, c-e). Fresh 

 water. Body measures 100 to 165 microns long. 



Genus Gastrostyla Engelmann, Body flexible; with broken 

 rows of ventral cirri. Fresh or salt water. 



Gastrostyla steini Engelmann (Fig. 166, /). Body about 

 220 microns long by 80 microns broad. 



Genus Onychodromus Stein. Inflexible body large, some- 

 what rectangular. Anterior end truncate; posterior end rounded. 

 Ventral surface flat; dorsal convex. Peristome broadly tri- 

 angular. Three frontals. Parallel to the right ridge of the peri- 

 stome run three rows of cirri in oblique direction. Five or six 

 anals. Marginals uninterrupted. Four to eight macronuclei; one 

 contractile vacuole. 



Onychodromus grandis (Fig. 166, g). Fresh water. Body 

 about 100 to 350 microns long. 



Genus Actinotricha Cohn. Body colorless, flexible; peri- 

 stome small. Its left border bears a small number of large 

 membranellae arranged in the form of a fan. Marine. 



Actinotricha saltans Cohn (Fig. 166, h). Salt water. Body 

 about 100 microns long. 



Family 3 Euplotidae Glaus 



Genus Euplotes Ehrenberg. Inflexible body ovoid; ventral 

 surface flattened; dorsal surface convex. Longitudinally ribbed. 

 Peristome broadly triangular and large; its right edge is slightly 

 drawn out. Nine or more frontal-ventrals, 5 anals, 4 scattered 



