POLYMASTIGIDA 



159 



stome and nucleus anterior. Three flagella of equal length 

 arise from the anterior end, the fourth trailing. Axostyle pro- 

 jects beyond the posterior end of body. All parasitic. 



Eutrichomastix serpentis (Dobell) (Fig. 60, a). In the large 

 intestine of several species of the snake belonging to the genera: 

 Pituophis, Eutaenia and Python. Body about 10 to 25 microns 

 long. 



Genus Retortamonas Grassi. Similar to Eutrichomastix in 

 possessing four flagella, one of which trails. Cytostome (?). 

 Axostyle indistinguishable; but a deeply staining axial filament 

 is noted in numerous specimens, although some lack it entirely. 

 Parasitic in the intestine of various insects. 



Fig. 60 a. Eutrichomastix serpentis. X1085 (After Kofoid and Swezy). 



b. Retortamonas orthopterorum. X 1 850 (After B6laf). 



c. Protrichomonas legeri. X750 (After Alexeleff). 



d. Polymastix melolonthae. X400 (After Hamburger). 



Retortamonas orthopterorum (Parisi) (Fig. 60, b). In cock- 

 roaches. Body very minute, 3 to 6 microns long. 



Genus Hexamastix Alexeieff. Body similar to Eutricho- 

 mastix, but there are six flagella, of which one trails. Axostyle 

 conspicuous and parabasal body prominent. 



Hexamastix hatrachorum Alexeieff. In amphibians. 



Genus Protrichomonas Alexeiefif. Three anterior flagella of 

 equal length, arising from a blepharoplast located at the ante- 

 rior tip. Parasitic, 



Protrichomonas legeri Alexeieff (Fig. 60, c). In the oeso- 

 phagus of the marine fish. Box hoops. 



Genus Polymastix Biitschli. Body pyriform. Four flagella 

 arise from two blepharoplasts located at the anterior end. 

 Cytostome and axostyle inconspicuous, but present. Ecto- 



