No. 2.] FRESH-WATER PROTOZOA. 43 



Straight, and on the other side indented so as to produce 

 openings through which ciha protrude. The anterior row 

 of plates is toothed ; the posterior row triangular, pressed 

 together like a roof. Mouth terminal, surrounded by a 

 row of strong cilia. Pharynx with a longitudinal striated 

 wall, a spherical nucleus, a secondary nucleus, and a sub- 

 terminal anus. 

 C. hirtus Elirbg., Fig. 153. 

 Anoplophrya Stein. 



Mouthless, free swimming, ovate to elongate. Nucleus 

 band-like. Contractile vacuoles well developed. Cilia 

 very long and uniform over the body. The animals are 

 parasites in the intestines of various animals. 

 An. sp. (?). ^ Fig. 226 represents a species of this genus 

 found freely swimming in a watering trough. Its host 

 being unknown, it is impossible to determine the species. 

 Holophrya Ehrbg. 



Ovate to cylindrical; rounded at both ends. Mouth 

 on the anterior end leading into a slightly developed 

 pharynx. Anus terminal, body striate, with a uniform 

 ciliation. 



A large number of minute ciliates have been found be- 

 longing apparently to this genus. Their great variability 

 makes the specific determination difficult and uncertain. 

 Figs. 1 19-123 represent some of these common types, but 

 no attempt has been made, at present, to determine the 

 species. The genus Holophyra is in many cases hardly 

 distinguishable from Enchelys, since the mouth is some- 

 times slightly excentric. Fig. 132 represents a spiral 

 ciliate with terminal mouth that is tentatively placed here. 

 Urotricha CI. & L. 



Like Holophyra, except that it possesses a terminal 

 posterior bristle. 

 U. farcta CI. & L., Fig. 127. 



Balantozoon agile of Stokes, Fig. 130, really belongs to this 

 genus. 

 Chaenia Duj. 



Elongated, narrowed in front, contractile. Mouth ter- 

 minal or sub-terminal, usually closed. No pharynx. Uni- 



