196 PROTOZOOLOGY 



Family 4 Chlorasteridae 



With 5 flajj;('lla arising from anterior pole. 



Genus Chloraster Ehrenbcrg. Similar to Pyramvnonas, but 

 anterior half with a conical envelope drawn out at four corners; 

 with 5 flagella; fresh or salt water. 



C. gyrans E. (Fig. 92, h). Up to 18At long; standing water; also 

 reported from salt water. 



Family 5 Polyblepharididae Dangeard 



With 6 or more flagella arising from anterior end. 



Genus Polyblepharides Dangeard. Ellipsoid or ovoid; flagella 

 6-8, shorter than body length; chromatophore; a pyrenoid; a 

 central nucleus; 2 contractile vacuoles anterior; cysts; a question- 

 able genus ; fresh water. 



P. singularis D. (Fig. 92, i). 10-14^ by 8-9^. 



Genus Pocillomonas Steinecke. Ovoid with broadly concave 

 anterior end; covered wdth gelatinous substance with numerous 

 small projections; 6 flagella; chromatophores disc-shaped; 2 

 contractile vacuoles anterior; nucleus central; starch bodies; 

 without pyrenoid. 



P. flos aquae S. (Fig. 92, j, k). 13/x by IO/jl; fresh water pools. 



Family 6 Phacotidae Poche 



The shell typically composed of 2 valves; 2 flagella protrude 

 from anterior end; with stigma and chromatophores; asexual re- 

 production within the shell; valves may become separated from 

 each other owing to an increase in gelatinous contents. 



Genus Phacotus Perty. Oval to circular in front view; lentic- 

 ular in profile; protoplasmic body does not fill dark-colored shell 

 completely; flagella protrude through a foramina; asexual repro- 

 duction into 2 to 8 individuals; fresh water. 



P. lenticularis (Ehrenberg) (Fig. 92, I, m). 13-20^ in diameter; 

 in stagnant water. 



Genus Pteromonas Sehgo. Body broadly winged in plane of 

 suture of 2 valves; protoplasmic body fills shell; chromatophore 

 cup-shaped; one or more pyrenoids; stigma; 2 contractile 

 vacuoles; asexual reproduction into 2-4 individuals; sexual re- 

 production by isogamy; zygotes usually brown; fresh water. 

 Several species. 



P. angulosa (Lemmermann) (Fig. 92, n). With a rounded wing 



