SPIROTRICHA, OLIGOTRICHA 817 



employed "forma" to distinguish forms in Entodinium with com- 

 mon 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 MacLennan (1930). 



The relationship between these oligotrichs and host ruminants has 

 not definitely been determined, but it appears to be commensalism 

 rather than symbiosis (Becker, Schulz and Emmerson, 1930; Mowry 

 and Becker, 1930). Morphology (Bretschneider, 1934, 1935); con- 

 tractile vacuoles (MacLennan, 1933); conjugation (Dogiel, 1925); 

 numbers in cattle stomach (Dogiel and Fedorowa, 1929); fauna in 

 African antelopes (Dogiel, 1932); in yaks (Dogiel, 1934); in Indian 

 goat (Das-Gupta, 1935); in Indian ox (Kofoid and MacLennan, 

 1930, 1932, 1933); in gaur (Kofoid and Christenson, 1934); in sheep, 

 wild sheep and goat (Ferber and Fedorowa, 1929; Bush and Kofoid, 

 1948). 



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 over the body length on right- 

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

 circles; macro nucleus simple, elongate; in the stomach of cattle, 

 sheep, goat and wild sheep (Ovis orientalis cycloceros) . Several spe- 

 cies (Kofoid and MacLennan, 1933); neuromotor system (Fernan- 

 dez, 1949). 



Dogiel (1927) designated the following species as 3 formae of 

 0. caudatus Eberlein. 



0. Ucoronatus Dogiel (Fig. 348, a). 120-1 70m by 81-90/*; primary 

 spine 38-58/* long; in sheep. 



O. caudatus Eberlein (Fig. 348, b). 137-162/* by 80-98/*; preanal 

 spines 47-60/* long; in sheep, goat, and cattle. 



O. quadricoronatus Dogiel (Fig. 348, c). 128-180/* by 86-100/*; 

 preanal spines 48-63/* long; in sheep and Ovis orientalis cycloceros. 



Genus Caloscolex Dogiel. Ovoid; anterior end truncate, posterior 

 end rounded with or without processes; 2 zones of membranellae; 

 dorsal zone encircles the body completely; 3 skeletal plates variously 

 modified; 7 contractile vacuoles in a single circle; nucleus elongate; 

 in the stomach of Camelus dromcdarius. Several species. 



C. cuspidatus D. (Fig. 348, d). 130-160/x by 73-90/*. 



Genus Entodinium Stein. Without dorsal zone; adoral zone at 

 truncate anterior end; without skeleton; contractile vacuole ante- 



