610 PROTOZOOLOGY 



D. hutschlii L. (Fig. 288, c). 135-155/1 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, subtermi^ial ; a micro nucleus; long 

 caudal cilia; in fresh water. 



L. hullinum P. (Fig. 288, d). 120-200/x long; posterior cilia 40-50^ 

 long. 



Genus Tetrahymena Furgason. Pyriform; small forms; uniform 

 ciliation; ciliary rows or meridians less than 20; 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 

 one species; conjugation unobserved; fresh water. Furgason (1940) 

 established this genus after making a comparative study with Leuco- 

 phrys, Glaucoma and Colipidium, as the most primitive genus of the 

 group. 



T. geleii F. (Figs. 288, e; 289, a, e, /). Pear to cucumber in shape; 

 40-60m long; 17-19 ciliary meridians; pyriform cytostome about 1/10 

 the body length; macronucleus irregularly ovoid; micronucleus un- 

 observed ; bacteria-feeder, but may be cultured in sterile media; pond 

 water. 



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

 (Fig. 38). Form and size vary; bacteria-feeders elongate pyriform, 

 50-75)u long; sap ro zoic forms fusiform, 30-70/x long, decreasing in 

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

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

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

 line irregular; a single micronucleus; pond water. 



Genus Leucophrys Ehrenberg. Broadly pyriform; cytostome large, 

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

 left margin; undulating membrane on right and 3 membranellae on 

 left of mouth; 5 postoral ciliary meridians; macronucleus ovoid; a 

 micronucleus; fresh water. 



L. patula E. (Figs. 288, /; 289, h, g). Broadly pyriform; 80-160m 

 long; occasionally small forms occur; cytostome pyriform, about 1/3 



