590 PROTOZOOLOGY 



C. cratera (Leidy) (Fig. 266, m). Lorica 60-70ju by 40/x; a num- 

 ber of varieties are often mentioned. 



Family 4 Ophryoscolecidae Stein 



Elongate oval, asymmetrical; with 1 or 2 (adoral and dorsal) 

 zones of membranellae; in digestive tract of mammals. Sharp 

 (1914) instituted use of "forma" to distinguish forms in Entodi- 

 nium with common characteristics differing in certain others, 

 which scheme was extended to the whole family by Dogiel (1927). 

 It is most probable that many species are varieties of a single 

 species as judged by the work of Poljansky and Strelkow (1934); 

 but since information is still incomplete, the present work ranks 

 various formae with species, in agreement with Kofoid and Mac- 

 Lennan (1930). 



Genus Ophryoscolex Stein. Ovoid; with adoral and dorsal 

 zones of membranellae; dorsal zone some distance behind anterior 

 end, encircling 3/4 the body circumference at middle, broken on 

 right ventral side; 3 skeletal plates extend the body length on 

 right-ventral side; 9-15 contractile vacuoles in 2 (anterior and 

 posterior) circles; macronucleus simple, elongate; in stomach of 

 cattle, sheep, goat and wild sheep (Ovis orientalis cycloceros). Sev- 

 eral species. Dogiel (1927) designated the following species as 3 

 formae of 0. caudatus Eberlein. 



0. hicoronatus Dogiel (Fig. 267, a). 120-170^ by 81-90^; pri- 

 mary spine 38-58/z long; in sheep. 



0. caudatus Eberlein (Fig. 267, h). 137-162ai by 80-98^; preanal 

 spines 47-60)u long; in sheep, goat, and cattle. 



0. quadricoronatus Dogiel (Fig. 267, c). 128-180m by 86-100^; 

 preanal spines 48-63iu long; in sheep and Ovis orientalis cyclo- 

 ceros. 



Genus Caloscolex Dogiel. Ovoid; anterior end truncate, post- 

 erior end rounded with or without processes; 2 zones of mem- 

 branellae; dorsal zone encircles the body completely; 3 skeletal 

 plates variously modified; 7 contractile vacuoles in a single circle; 

 nucleus elongate; in stomach of Canielus dromedarius. Several 

 species. 



C. cuspidatus D. (Fig. 267, d). 130-1 60m by 73-90^. 



Genus Entodinium Stein. Without dorsal zone; adoral zone at 

 truncate anterior end; without skeleton; contractile vacuole an- 

 terior; macronucleus, cyUndrical or sausage-form, dorsal; mi- 



