272 PROTOZOOLOGY 



P. scroa Kirby (Fig. 126, k). 18-45m by 6-1 5/x; in Kalotermes 

 dudleyi and K. longicollis ; Panama. 



Gonus Pseudotrypanosoma Grassi. Large, elongate; 3 anterior 

 flagella; undulating membrane; slender axostyle; costa conspicu- 

 ous; band-like structure between blepharoplast and nucleus; 

 striae near body surface; parabasal body long; parasitic. 



P. giganteum G. (Fig. 126, I). 55-1 ll/x long (Grassi); 145-205^ 

 by 20-40/i; anterior flagella about 30)U long (Kirby); cytostome 

 not observed; in gut of Porotermes adamsoni and P. grandis; 

 Australia. 



Suborder 2 Diplomonadina 



The suborder consists of a number of binucleate flagellates 

 possessing bilateral symmetry. 



Family Hexamitidae Kent 



Genus Hexamita Dujardin {Octomitus Prowazek). Pyriform; 2 

 nuclei at anterior pole, 6 anterior and 2 posterior flagella; 2 

 axostyles; 1-2 contractile vacuoles; cytostome obscure; endo- 

 plasm with refractile granules; encystment; in stagnant water 

 or parasitic. 



H. inflata D. (Fig. 127, a). Broadly oval; posterior end trun- 

 cate; 13-25m by 9-15^; in stagnant water. 



H. iiitestinalis D. (Fig. 127, h, c). 10-16m long; in intestine of 

 frogs, also in midgut of Trutta fario and in rectum of Motella 

 tricirrata and M. mustela in European waters. 



H. salmonis (Moore) (Fig. 127, d). 10-12/i by 6-8/^; in intestine 

 of various species of trout and salmon; schizogony in epithelium 

 of pyloric caeca and intestine; cysts; pathogenic to young host 

 fish (Davis, 1925). 



H. periplanetae (Belaf) In gut of cockroaches. 



H. cryptocerci Cleveland (Fig. 127, e). 8-13/i by 4-5. 5m; in 

 Cryptocercus puntulatus. 



Genus Giardia Kunstler {Lamhlia Blanchard). Pyriform; bi- 

 laterally symmetrical; dorsal side convex; ventral side with 

 sucking disc at anterior region; 8 flagella; 4 from margin of suck- 

 ing disc; 2 from middle part and 2 from posterior end of body; 

 parasites in intestine of various vertebrates. Several species. 



G. intestinalis (Lambl) (Fig. 127, f-h). 10-20m by 6-10/x; com- 

 mensal in human intestine. 



G. muris (Grassi). 7-13^ by 5-10ai; in intestine of mice and rats. 



