244 university of colorado studies 



Suborder Trichostomina 



In addition to the general coating of cilia there is usually an undulating membrane 

 (or membranes) at edge of mouth or in the pharynx. The mouth is always open 

 (Calkins). 



Family COLPODIDAE (chiliferid^) 

 Mouth anterior or central; pharynx short or absent. 



(66) Frontonia Ehrenberg. Elongate-oval or elliptical; mouth lateral, appear- 

 ing as a slit-like opening; pharynx short, with minute teeth; surface striated 

 longitudinally (Edmondson). F. leiicas Ehr.* Length 250-300 /*. (F. elliptica 

 Beardslej'^ occurs near Greeley.) 



(67) Loxocephalus Eberhard. Elongate, with more or less parallel sides, and 

 with a long caudal and a pair of lateral setae, the caudal like a stiff flagellum. 

 L. granulosus S. Kent.* 



(68) Colpoda Miiller. More or less kidney-shaped, or with one side more or less 

 concave, the other convex. Mouth a minute cleft-like depression. 



C. helia Stokes*; C. catnpyla Stokes.* 



(69) Glaucoma Ehrenberg. Dorsal side convex, ventral flattened and ciliated; 

 contractile vesicle single. G. scintillans Ehr.* 



Family MICROTHORACID.ffi 

 Small asymmetrical forms, with the mouth invariably in the hinder portion. The 

 ciha are always more or less dispersed, sometimes limited to the oral region 

 (Calkins). 



(70) Cinetochilum Perty. Broad and short, with blunt ends; dorsal surface with 

 oblique furrows; cilia on ventral surface; a number of hair-like setas projecting 

 obhquely posteriorly. C. margaritaceum (Ehrenberg).* 



Family PARAM^CIID^ 

 Elongate-oval, entirely clothed with cilia; mouth at the end of a large oblique 

 oral groove. 



(71) Paramaecium Miiller. P. caudatum Ehr.*; P. trichium Stokes. 



Jennings and Hargitt {Journal of Morphology, December, 1910) have published 

 a most interesting paper on the diverse races of Paramecium. They find that 

 P. caudatum has one micronucleus, whereas P. aurelia has two. Several distinct 

 races of P. caudatum were obtained; the largest was 180 to 230 m long. P. 

 trichium is shorter and broader than P. caudatum; its length is 75-100 m. 



Family PLEURONEMID^ 

 Mouth at the posterior end of a ventral furrow or peristome. 



(72) Lembadion Perty. Oval but flattened; peristome occupying the greater 

 part of the ventral surface; a tuft of rigid cilia posteriorly. L. bidlinum Perty.* 



(73) Cyclidium Miiller. Cilia very long, about as long as the diameter of the 

 body; a long posterior seta. C. glaucoma Ehr.* There is some doubt about the 

 identity of the animals described by Muller and Ehrenberg, but our species is 

 the same as Ehrenberg's. 



