314 



PROTOZOOLOGY 



G. muris (Grassi). 7-13ai by 5-1 Om; in the intestine of mice and 

 rats. 



Genus Trepomonas Diijardin. Free-swimming; flattened; more or 

 less rounded; cytostomal grooves on posterior half, one on each side; 

 8 flagella (one long and 3 short flagella on each side) arise from ante- 

 rior margin of groove; near anterior margin there is a horseshoe-form 

 structure, in which two nuclei are located; fresh water, parasitic, 

 or coprozoic. 



T. agilis D. (Fig. 147, /). More or less ovoid; 7-30/x long; 1 long 

 and 3 short flagella on each side; rotation movement; stagnant 

 water; also reported from intestine of amphibians. 





Fig. 148. Giardia intestinalis, X1150 (Kudo). 1, 2, living trophozoites 

 in front and side views; 3, 4, stained trophozoites in front and side views; 

 5, a fresh cyst; 6, 7, stained cysts; 8, a stained cyst in an end view. 



T. rotans Klebs (Fig. 147, g). Broadly oval; posterior half highly 

 flattened; 2 long and 2 short flagella on each of 2 cytostomes; stag- 

 nant water. 



Genus Gyromonas Seligo. Free-swimming; small; form constant, 

 flattened; slightly spirally coiled; 4 flagella at anterior end; cyto- 

 stome not observed; fresh water. 



G. ambulans S. (Fig. 147, h). Rounded; 8-1 5/i long; standing 

 water. 



Genus Trigonomonas Klebs. Free-swimming; pyriform, plastic; 

 cytostome on either side, from anterior margin of which arise 3 

 flagella; flagella 6 in all; 2 nuclei situated near anterior end; move- 

 ment rotation; holozoic; fresh water. 



