594 PROTOZOOLOGY 



longitudinal plates beneath left surface, with anterior ends con- 

 nected by cross bars; contractile vacuoles beneath dorsal surface 

 in a longitudinal row, also with additional vacuoles; in stomach 

 of cattle and sheep. 



P. midtivesicnlatum (D. et Fedorowa) (Fig. 269, a). 120-190yu 

 by 78-140/i; in cattle and sheep. MacLennan (1934) found that 

 the skeletal plates are made up of small, roughly prismatic blocks 

 of glycogen, each with a central granule. 



Genus Elytroplastron Kofoid et MacLennan. 2 zones at ante- 

 rior end, 2 skeletal plates beneath right surface, a small plate be- 

 neath ventral surface, and a long plate below left side; pellicle 

 and ectoplasm thick; conspicuous fibrils beneath dorsal and 

 right sides. One species. 



E. huhali (Dogiel) (Fig. 269, h). 110-160^ by 67-97^; in cattle, 

 sheep, Buffelus buhalus and Bos indicus. 



Genus Ostracodinium Dogiel. 2 zones at anterior end; broad 

 skeletal plate beneath right side; 2-6 contractile vacuoles in a 

 dorsal row; cytopharyngeal fibrils thick, extend to posterior end; 

 in cattle, sheep, antelope, steenbock, and reindeer, Numerous 

 species. 



0. dentatum (Fiorentini) (Fig. 269, c). 52-1 lO/x by 31-68^; in 

 stomach of cattle. 



Genus Enoploplastron Kofoid et MacLennan. 2 zones near an- 

 terior end; 3 skeletal plates beneath right and ventral sides, either 

 separate or partly fused; 2 contractile vacuoles; heavy pharyn- 

 geal fibrils; in cattle, reindeer and antelope. 



E. triloricatum (Dogiel) (Fig. 269, d). Dogiel (1927) mentions 

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

 lows: in cattle, 85-1 12^ by 51-70yu; in reindeer, 75-103^ by 40- 

 58/^; in antelope (Rhaphiceros sp.), 60-110^ by 37-56^. 



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 con- 

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



E. caudatum (Fiorentini) (Fig. 269, e). 113-151iu by 45-61/i; 

 in cattle, camels, Cervus canadensis and reindeer. 



E. (Diplodinium) ecaudatum (F.) (Figs. 16; 269,/). 112-140/x 

 by 40-60^1 (Becker and Talbott); in cattle, sheep, and reindeer. 

 The classical observation of Sharp (1914) on its neuromotor sys- 

 tem has been described elsewhere (p. 55). 



