No. 2.] FRESH-WATER PROTOZOA. 59 



U. longicaudattis Stokes, Fig. 232. 

 U. musculus Ehrbg., Fig, 233. 

 U. musculus (?), Fig. 234. 

 U. dispar Stokes, Fig. 243. 

 Platytrichotus Stokes. 



Like Uroleptus, but body flask-shaped. Frontal styles 

 five ; two rows of ventral cilia, and no anal cilia. Border 

 cilia uninterrupted. 

 PI. opisthobohts Stokes, Fig. 238. 

 Pleurotricha Stein. 



Not contractile, rounded at both ends ; somewhat oval 

 in outline, with eight sternal cilia. Ventral cilia arranged 

 in two rows ; five anal cilia, of which the two on the right 

 side are near the end of the body. Border cilia an un- 

 broken row. Between the border cilia and the ventral 

 cilia, upon one or both sides, are one to three accessory 

 rows of bristle-like cilia. Upper lip developed ; peristome 

 broad, one-third the length of the body. 

 Pl.sp. (?),Fig. 235. 

 Onychodromus Stein. 



Not flexible. In outline somewhat rectangular, with 

 slightly rounded ends. Ventral surface flat, dorsal sur- 

 face convex. Peristome broad, three-angled, reaching to 

 the middle of the body. Upper lip present. On the right 

 anterior end three strong cilia behind which are three rows 

 of cilia parallel with the right edge of the peristome. 

 Three or four oblique rows of ventral cilia, running from 

 right to left ; five or six strong anal cilia ; border cilia un- 

 interrupted. Upon the dorsal surface two processes. 

 Four to eight nuclei and one contractile vacuole. 

 On. grandis Stein, Fig. 247. 

 Urosoma Kow. 



Similar to O.rytricha, but with eight ventral cilia. 

 Posterior extremity prolonged, with five to eight cilia at 

 the beginning of the prolongation. 

 U. cienkozvski Kow., Fig. 248. This is provisionally re- 

 ferred to this genus. Only one specimen yet found. 

 Oxytricha Ehrbg. (Stein, Sterki). 



Narrow elliptical, rounded at both ends. Ventral sur- 



