296 



PROTOZOOLOGY 



Family 2 Tetramitidae Blitschli 



Genus Tetramitus Perty. Ellipsoidal or pyriform; free-swimming; 

 cytostome at anterior end; 4 flagella unequal in length; a contractile 

 vacuole; ho lo zoic; fresh or salt water. 



T. rostratus P, (Fig. 135, a). Form variable; usually ovoid with 

 narrow posterior region; IS-SOju by 8-1 Iju; stagnant water. Bunting 

 (1922, 1926) observed a very interesting life-cycle of an organism 

 which she found in culture of caecal contents of rat and which she 

 identified as T. rostratus (Fig. 134). 



Fig. 135. a, Tetramitus rostratus, X620 (Lemmermann) ; b, T. pyri- 

 formis, X670 (Klebs); c. T. salinus, X1630 (Kirby); d, Collodidijon 

 triciliatum, X400 (Carter); e-j, Costia necatrix (e, f, X800 (Weltner); 

 g-i, X1400 (Moroff); j, two individuals attached to host integument 

 X500 (Kudo)); k, Enteromonas hominis, X1730 (Wenyon and O'Con- 

 nor); 1, Copromastix prowazeki, X1070 (Aragao). 



T. pyriformis Klebs (Fig. 135, b). Pyriform, with pointed poste- 

 rior end; 11-13/i by 10-12/x; stagnant water. 



T. salinus (Entz) (Fig. 135, c). 2 anterior flagella, 2 long trailing 

 flagella; nucleus anterior; cytostome anterior to nucleus; a groove to 

 posterior end; cyto pharynx temporary and length variable; 20-30)u 

 long (Entz); 15-19^ long (Kirby), Kirby observed it in a pool with 

 a high salinity at Marina, California. 



Genus Collodictyon Carter. Body highly plastic; with longitudinal 



