SPIROTRICHA, OLIGOTRICHA 659 



cytopharyngeal fibrils thick, extend to posterior end; in cattle, sheep, 

 antelope, steenbok, and reindeer. Numerous species. 



0. dentatum (Fiorentini) (Fig. 310, c). 52-110^ by 31-68^; in 

 the stomach of cattle. 



Genus Enoploplastron Kofoid and MacLennan. 2 zones near an- 

 terior end; 3 skeletal plates beneath right-ventral side, either 

 separate or partly fused; 2 contractile vacuoles; heavy pharyngeal 

 fibrils; in cattle, reindeer and antelope. 



E. triloricatum (Dogiel) (Fig. 310, d). Dogiel (1927) mentions size 

 differences among those occurring in different host species, as fol- 

 lows: in cattle, 85-112/i by 51-7 0^; in reindeer, 75-103ju by 40-58^; 

 in antelope (Rhaphiceros sp.), 60-1 lO/x by 37-56ju. 



Genus Epidinium Crawley. Elongate; twisted around the main 

 axis; 2 zones; dorsal zone not at anterior end; 3 skeletal plates, with 

 secondary plates; simple macronucleus club-shaped; 2 contractile 

 vacuoles; in cattle, sheep, reindeer, camels, etc. 



E. caudatum (Fiorentini) (Fig. 310, e). 113-151^ by 45-61^; in 

 cattle, camels, Cervus canadensis and reindeer. 



E. {Diplodinium) ecaudatum (F.) (Figs. 16; 310,/). 112-140/x by 

 40-60/x (Becker and Talbott); in cattle, sheep, and reindeer. The 

 classical observation of Sharp (1914) on its neuromotor system has 

 been described elsewhere (p. 54). 



Genus Epiplastron Kofoid and MacLennan. Elongate; 2 zones; 

 dorsal zone not at anterior end; 5 skeletal plates, with secondary 

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

 antelopes. 



E. africanum (Dogiel) (Fig. 310, g). 90-140^ by 30-55^; in Rha- 

 phiceros sp. 



Genus Ophisthotrichum Buisson. 2 zones; dorsal zone at middle 

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

 2 contractile vacuoles posterior; conjugation (Dogiel); in many Afri- 

 can antelopes. One species. 



0. janus (Dogiel) (0. thomasi B.) (Fig. 311, a). 90-150m by 42-60m. 



Genus Cunhaia Hasselmann. Cytostome near anterior end, with 

 adoral zone; dorsal zone on 1/3 of anterior-dorsal surface; 2 con- 

 tractile vacuoles; skeleton (?); in the caecum of guinea pig, Cavia 

 aperea. One species. 



C. curvata H. (Fig. 311,6). 60-80m by 30-40/x; in Brazil. 



Family 5 Cycloposthiidae Poche 



Pellicle firm and body rigid; zones of membranellae at anterior 

 and posterior ends; more or less compressed; cytopharynx short 



