MASTIGOPHOEA 27 



M. verrucosa Kent (Fig. 23). Length about .015 mm.; many short 

 pseudopodia: in fresh water. 



M. simplex Calkins. Ectosarc and entosarc distinct; flagellum 

 converted into a pseudopodium ; length .01 mm.: marine, on decaying 

 algae. 



FAMILY 2. CEKCOMONADIDAE. 



Body oval or elongate, frequently amoeboid, especially at hinder 

 end; with pseudopodia and with a long flagellum: 5 genera. 



1. CERCOMONAS Dujardin. Form more or less spindle-shaped, pro- 

 longed posteriorly: 3 species; in fresh water. 



C. longicauda Duj. Tail long; length up to .05 mm. 



Fig. 23 Fig. 24 Fig. 25 



Fig. 23 Mastigamceba verrucosa (Calkins). Fig. 24 Herpetomonas muscae 

 domesticae (Doflein). Fig. 25 Codoneca gracilis (Calkins). 



2. HERPETOMONAS Kent. Body elongate, very flexible; hinder end 

 often the more attenuate, but not forming a caudal filament: several 

 species; parasitic in insects. 



H. muscae domesticae (Burnett) (Fig. 24). Length .05 mm.: in 

 intestine of the house-fly; common. 



3. OIKOMONAS Kent. Form spherical or oval; frequently a pro- 

 jecting lip at base of flagellum; sometimes attached by a terminal fila- 

 ment : several species in fresh and salt water, often in infusions. 



0. termo (Ehrenberg). Length .06 mm.: often very common in 

 fresh water. 



FAMILY 3. CODONECIDAE. 



Body enclosed in a gelatinous or hyaline cup: 2 genera. 



CODONECA Clark. Ovoid or goblet-shaped, and attached to a caudal, 

 stalk; animal does not fill cup: 3 species; in fresh and salt water. 



C. gracilis Calkins (Fig. 25). Cup urn-shaped with a distinct neck; 

 length .021 mm.: Woods Hole. 



FAMILY 4. HETEKOMONADIDAE. 



One or 2 accessory flagella present besides the main one; often 

 sessile or colonial, the animals being on a common stalk: 3 genera. 



