HOLOTRICHA 



611 



the body length; 40-45 ciliary meridians; macro nucleus irregularly 

 ovoid; a micro nucleus attached to macro nucleus; carnivorous, but 

 may be cultured in sterile media (Kidder); fresh water. 



Genus Glaucoma Ehrenberg (Dallasia Stokes). Ovoid or ellipsoid; 

 cytostome about one-fourth the body length, near anterior end, 

 ellipsoid; cytostome with an inconspicuous undulating membrane 

 on right and 3 membranellae on left; ectoplasmic ridge on right bor- 

 der of mouth; ciliation uniform; 30-40 ciliary meridians; 7 postoral 

 meridians; macro nucleus rounded; a micro nucleus; a contractile 

 vacuole; with or without 1 or more caudal bristles; fresh water. 



Fig. 289. Diagrammatic oral views and oral apparatus of four genera. 

 Ciliary meridians of: a, Tetrahymena geleii; b, Leucophrys patula; c, Glau- 

 coma scintillans; and d, Colpidium campijlum. All X about 535. e, cyto- 

 stome of Tetrahymena geleii, showing the ectoplasmic ridge and 3 mem- 

 branellae on left and a large undulating membrane on right. Diagrams 

 of cytostome of: f, T. geleii; g, Leucophrys patula; h, Glaucoma scintillans; 

 and i, Colpidium colpoda. (a, c, d, modified after Kidder; b, e-i, modified 

 after Furgason.) 



G. scintillans E. (Fig. 289, c, h). Ovate with rounded ends; 45-75/x 

 long; U-shaped cytostome, about one-fourth the body length, ob- 

 lique; ectoplasmic flange and 3 membranellae conspicuous; a con- 

 tractile vacuole in posterior one-third; macro nucleus oval, central; 

 a micro nucleus; bacteria-feeder, but cultivable in bacteria-free 

 •culture media (Kidder) ; fresh water. 



Genus Colpidium Stein. Elongate reniform; ciliary meridians 

 variable in number, but typically one postoral meridian; small tri- 



