MASTIGOPHORA 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. CERCOMONADIDAE. 



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-fl}-; 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. HETEROMONADIDAE. 



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

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



