154 



BIOLOGY OF THE PROTOZOA 



different species; sometimes they form a complete coating for the 

 organism as in the majority of Holotrichida (Fig. 84); sometimes 

 they are limited to certain zones as in Urocentrum turbo, Didinium 



B 



Fig. 84.— Types of Ciliata. A, Monodinium balbianii; B, Cyclotrichium sphaericum, 

 C, Dinophrya lieberkuhni; D, Askenasia elegans. (After Faure-Fremiet.) 



nasutum, etc. (Fig. 205, p. 504) ; or sometimes to the ventral surface, 

 as in generalized Hypotrichida (Fig. 88, p. 159). In all cases they are 

 arranged in longer or shorter rows running straight or spirally, and 



