760 PROTOZOOLOGY 



D. biitschlii L. (Fig. 323, e). 135-155^ long; with or without zoo- 

 chlorellae; in fresh water. 



Genus Lembadion Perty. Oval; dorsal side convex, ventral side 

 concave; cytostome 3/4-4/5 the body length; on its left with a large 

 membrane composed of many ciliary rows and on its right, numerous 

 narrow rows of short free cilia; an undulating membrane and ciliary 

 rows near posterior end; contractile vacuole in mid-dorsal region 

 with a long tubule opening at posterior-right side; close ciliation 

 uniform; macronucleus ellipsoid, subterminal; a micro nucleus; long 

 caudal cilia; in fresh water. 



L. bullinum P. (Fig. 323, /). 120-200^ long; posterior cilia 40-50/x 

 long. 



Genus Tetrahymena Furgason (1941). Pyriform; small forms; uni- 

 form ciliation; ciliary rows or meridians 17-42; 2 postoral meridians; 

 preoral suture straight; cytostome small, close to anterior end, pyri- 

 form; its axis parallel to body axis; inconspicuous ectoplasmic ridge 

 or flange on the left margin of mouth; an undulating membrane on 

 right side and 3 membranellae on left of the cytostome; a single con- 

 tractile vacuole; macronucleus ovoid; micronucleus absent in some 

 species; in fresh water or parasitic. Corliss (1952, 1952a) made a 

 comparative study of different strains and allied forms. 



T. pyriformis (Ehrenberg) (T. geleii Furgason) (Figs. 323, g; 324, 

 a-c). 59 strains (Corliss, 1952a) ; 40-60/x long; 17-23 ciliary meridians; 

 pyriform cytostome about 1/10 the body length; with or without 

 micronucleus; bacteria-feeder; in fresh water (Corless, 1952, 1952a). 

 Bacteria-free or pure culture (Kidder, 1941) (p. 884). 



T. vorax (Kidder, Lilly and Claff) (Glaucoma vorax K. L. and C.) 

 (Fig. 39). Form and size vary; bacteria-feeders elongate pyriform, 

 50-75ju long; saprozoic forms fusiform, 30-70/z long, decreasing in 

 size with the age of culture; sterile particle-feeders, 60-80/z long; 

 carnivores and cannibals broadly pyriform, 100-250^ long; 19-21 

 ciliary meridians; macronucleus ovoid, central; in carnivores, out- 

 line irregular; apparently without micronucleus; pond water. 



T. limacis (Warren). In the liver and other visceral organs of the 

 gray garden slug, Deroceras agreste; 33-68 (55) n by 18-35(27)//; 

 those from cultures measure 28-68(44) n by 1 7-42(27) /x; the parasitic 

 phase is cucumber-shaped with apiculate anterior end ; the free-living 

 organisms are pyriform, somewhat pointed anteriorly; cytostome at 

 about 1/4 from the anterior end, with an undulating membrane and 

 three membranelles; 33-37 ciliary rows (Kozloff, 1946). 



Genus Leucophrys Ehrenberg. Broadly pyriform; cytostome large, 

 pyriform, with its axis parallel to body axis; ectoplasmic flange along 



