390 PROTOZOOLOGY 



has been found within nematodes which coinhabit the host intestine. 

 For example, Theiler and Farber (1932) found the flagellate in the 

 chyle-stomach of Aspicularis tetraptera and Syphacia obvelata, and 

 Becker (1933) noted two active individuals of this flagellate within 

 the egg shell of the last-named nematode. Morphology and division 

 (Kofoid and Swezy, 1915; Wenrich, 1921). 



T. caviae (Davaine). Ovoid or pyriform; 5-22/z long; undulating 

 membrane long; axostyle protrudes; spherical cysts about 7 m in di- 

 ameter (Galli-Valerio, 1903; Wenyon, 1926). Cytology and reproduc- 

 tion (Grasse and Faure, 1939). 



T. batrachorum (Perty) (Fig. 166, e). Ovoid; 14-18/* by 6-10/x 

 (Alexeieff); in culture, 7-22/z by 4-7 ju (Bishop, 1931) ; axostyle with- 

 out granules; in the colon of frogs and toads. Bishop (1934) suc- 

 ceeded in infecting the tadpoles of Rana temporaria and Bufo vul- 

 garis by feeding them on cultures free from cysts. 



T. augusta Alexeieff (Fig. 166, /, g). Elongate spindle; 15-27/x by 

 5-13/z; thick axostyle protrudes, and contains dark-staining gran- 

 ules; in the colon of frogs and toads. Morphology and division 

 (Kofoid and Swezy, 1915; Samuels, 1941); viability (Rosenberg, 

 1936); in frog liver lesions (Stabler and Pennypacker, 1939). 



T. brevicollis Kirby (Fig. 166, h). Ovoid, undulating membrane 

 curved around end; 10-1 7m by 4-8m; in the intestine of Kalotermes 

 brevicollis; Panama. 



Genus Pseudotrichomonas Bishop. Body form, structure and 

 movement, are exactly like those of Tritrichomonas, but free-living 

 in freshwater pond (Bishop, 1939). 



P. keilini B. (Fig. 166, i, j). When alive 7-11m by 3-6m; highly 

 plastic; young cultures contain more globular forms, while old cul- 

 tures more elongated organisms; three unequally long anterior flag- 

 ella; undulating membrane short, does not extend more than 1/2 

 the body and without a free flagellum; cytostome; holozoic, feeding 

 on bacteria; nucleus anterior; axostyle filamentous, invisible in life; 

 no cysts; in a pond in Lincolnshire, England. Bishop (1935) culti- 

 vated this flagellate in serum-saline medium, in hay infusion and in 

 pond or rain water with boiled wheat grains at 4-31°C. (Bishop, 

 1936, 1939). 



Genus Tricercomitus Kirby. Small; 3 anterior flagella; a long 

 trailing flagellum, adhering to body; nucleus anterior, without 

 endosome; blepharoplast large, with a parabasal body and an axial 

 filament; parasitic. 



T. termopsidis K. (Fig. 167, b). 4-12/x by 2-3m; anterior flagella 

 6-20m long; trailing flagellum 19-65m long; in gut of Zootermopsis 



