SPIROTRICHA, OLIGOTRICHA 



595 



Fig. 269. a, Poly-plastron multivesiculatum, X360 (Dogiel); b, Elytro- 

 j)lastron 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, Epiplaslron africanum, X300 (Dogiel). 



Genus Epiplastron Kofoid et MacLennan. Elongate; 2 zones, 

 dorsal zone behind anterior end; 5 skeletal plates, with secondary 

 plates; macronucleus simple, elongate; 2 contractile vacuoles; in 

 antelopes. 



E. africanum (Dogiel) (Fig. 269, g). 90-140m by 30-55yu; in 

 Rhaphiceros sp. 



Genus Ophisthotrichum Buisson. 2 zones, dorsal zone at mid- 

 dle or near posterior end of body; one-piece skeletal plate well 

 developed; 2 contractile vacuoles posterior; conjugation (Dogiel); 

 in many African antelopes. One species. 



0. janus (Dogiel) (0. thomasi B.) (Fig. 270, a). 90-150m by 42- 

 60m. 



