HOLOTRICHA 763 



cal macro nucleus central; a micro-nucleus; a single contractile vacu- 

 ole; body 40-50/x long; fresh water. 



Genus Espejoia Burger (Balantiophorus Penard). Ellipsoid; an- 

 terior end obliquely truncate; large cytostome at anterior end; post- 

 oral groove on ventral side, 1/4-1/3 the body length ; a conspicuous 

 membrane on the left edge of groove; in gelatinous envelope of eggs 

 of insects and molluscs. 



E. musicola (P.) (Fig. 325, a). Elongate; right side flat, left side 

 convex; 80-100^ long (Penard); 70-80m long and dimorphic (Faure- 

 Fremiet and Mugard, 1949). 



Genus Cryptochilidium Schouteden (Cryptochilum Maupas). El- 

 lipsoid; with rounded anterior end, posterior end pointed in profile; 

 highly compressed; uniform and close ciliation; cytostome near mid- 

 dle; one or more longer cilia at posterior end; contractile vacuole 

 posterior; macronucleus round; a micronucleus; commensal. Several 

 species (Powers, 1933, 1935). 



C. echini (Maupas) (Fig. 325, b). 70-140m long; in the gut of Echi- 

 nus lividus. 



Genus Eurychilum Andre. Elongate ellipsoid; anterior end some- 

 what narrowed; cilia short; dense ciliation not in rows; contractile 

 vacuole terminal; macronucleus band-form; cytostome about 2/5 

 from anterior end and toward right, with a strong undulating mem- 

 brane on left; no cyto pharynx; actively swimming. One species. 



E. actiniae A. (Fig. 325, c). About 155/x long; in gastrovascular 

 cavity of Sagartia parasitica. 



Genus Monochilum Schewiakoff. Ovoid to ellipsoid; medium 

 large; uniform and dense ciliation in rows; oblong cytostome left of 

 median line, in about 1/4 the body length from anterior end; short 

 cyto pharynx conical, with an undulating membrane; contractile 

 vacuole near middle; in fresh water. 



M. frontatum S. (Fig. 325, d). Anterior end broader; ventrally 

 flattened, dorsally somewhat convex; macronucleus ellipsoid; a 

 micronucleus; feeds on algae; 80/* by 30/u. 



Genus Dichilum Schewiakoff. Similar to Monochilum; but mem- 

 brane on both edges of the cytostome; in fresh or salt water. 



D. cuneiforme S. (Fig. 325, e). Ellipsoid; cytostome about 1/5 the 

 body length from anterior end; right membrane larger than left; 

 small cytopharynx; macronucleus ellipsoid; about 40/x by 24ju; in 

 fresh water. 



Genus Loxocephalus Eberhard. Ovoid to cylindrical; sometimes 

 compressed; crescentic cytostome on slightly flattened area near 

 anterior end, with 2 membranes; often a zone of cilia around body; 



