160 



HANDBOOK OF PROTOZOOLOGY 



plasm is covered by longitudinally placed ridges. Parasitic 

 in insects. 



Polymastix melolonthae (Grassi) (Fig. 60, d). In the gut 

 of the larvae of the cockchafer. 



Group 4 



Genus Chilomastix Alexeieff. Body pyriform, with a large 

 cytostopial cleft at the anterior end. Nucleus anterior. Three 

 anteriorly directed flagella and fourth flagellum undulates 

 within the cleft. Cysts are common. In the intestine of verte- 

 brates. 



Fig. 61 a-c. Chilomastix mesnili. X800. a, living individual; 

 b, a stained specimen; c, a stained cyst. 



d. Trichomo7ias hominis. X800. 



e. T. elongata. X800. 



f. T. vaginalis. X650 (After Wenyon). 



g. Ditrichomonas termitis. X470 (After Cutler), 

 h. Giantomonas herculea. X400 (After Dogiel). 



i. Myxomonas polymorpha. X300 (After Dogiel). 



Chilotnaslix mesnili (Wenyon) (Fig. 61, a-c). In the human 

 intestine; held to be a commensal, although often found in 

 abundance in diarrhoeic stools. Length 10 to 15 microns long. 

 Cysts measure 5 to 10 microns in length. 



Group 5 



Genus Trichomonas Donne. Body pyriform. Anterior 

 Hagella 3 or 4 in number; another flagellum runs along the outer 



