660 PROTOZOOLOGY 



and wide; macronucleus elongate; a single micronucleus; 2 or more 

 contractile vacuoles; in horse and anthropoid apes. 



Genus Cycloposthium Bundle. Large, elongate barrel-shaped; 

 cytostome in center of a retractile conical elevation at anterior end; 

 adoral zone conspicuous; an open ring-zone of membranellae near 

 posterior end on both dorsal and ventral sides ; pellicle ridged ; skele- 



FiG. 310. a, Polyplastron multivesiculatuvi, X360 (Dogiel); b, Ely- 

 troplastron bubali, X340 (Dogiel); c, Ostracodinium dentatum, X440 

 (Dogiel); d, Enoploplastron triloricatum, X370 (Dogiel); e, Epidinium 

 caudatum^ X340 (Becker and Talbott); f, E. ecaudatum, X340 (Becker 

 and Talbott); g, Epiplastron ajricanum, X300 (Dogiel), 



ton club-shaped; several contractile vacuoles in a row along band- 

 form macronucleus; in the caecum and colon of horse. Many species. 



C. bipalmatum (Fiorentini) (Fig. 311, c). 80-1 27/x by 35-57^. 



C. dentiferum Gassovsky (Fig. 311, t^). 140-222^ by 80-1 lO/x. 



Genus Spirodinium Fiorentini. Elongate, more or less fusiform; 

 adoral zone at anterior end, zone making at least one complete spiral 



