224 PROTOZOOLOGY 



Genus Polytomella Aragao. Ellipsoid, or oval, with a small papilla 

 at anterior end, where 4 equally long flagella arise; with or without 

 stigma ; starch ; fresh water. 



P. agilis A. (Fig. 98, c, d). Numerous starch grains; S-lS^t by 

 5-9/x; flagella 12-17/x long; fresh water; hay infusion. 



P. caeca Pringsheim. Ovoid with bluntly pointed posterior end; 

 12-20m by 10-12^; membrane delicate; a small papilla at anterior 

 end; no stigma; two contractile vacuoles below papilla; cytoplasm 

 ordinarily filled with starch grains ; fresh water. 



Genus Medusochloris Pascher. Hollowed hemisphere with 4 proc- 

 esses, each bearing a flagellum at its lower edge; a lobed plate- 

 shaped chromatophore; without pyrenoid below convex surface. 

 One species. 



M. phiale P. In salt water pools with decaying algae in the Baltic. 



Genus Spirogonium Pascher. Body spindle-form; membrane deli- 

 cate; flagella a little longer than body; chromatophore conspicuous; 

 a pyrenoid; stigma anterior; 2 contractile vacuoles; fresh water. One 

 species. 



S. chlorogonioides (P). (Fig. 98, e). Body up to 25m by 15m. 



Genus Tetrablepharis Senn. Ellipsoid to ovoid; pyrenoid present; 

 fresh water. 



T. multifilis (Klebs) (Fig. 98,/). 12-20m by 8-15m ; stagnant water. 



Genus Spermatozopsis Korschikoff. Sickle-form; bent easily, oc- 

 casionally plastic; chromatophore mostly on convex side; a distinct 

 stigma at more rounded anterior end; flagella equally long; 2 con- 

 tractile vacuoles anterior; fresh water infusion. 



S. exultans K. (Fig. 98, g). 7-9m long; also biflagellate; in fresh 

 water with algae, leaves, etc. 



Family 4 Chlorasteridae 



With 5 flagella arising from anterior pole. 



Genus Chloraster Ehrenberg. Similar to Pyramimonas, but an- 

 terior half with a conical envelope drawn out at four corners; with 5 

 flagella ; fresh or salt water. 



C. gyrans E. (Fig. 98, h). Up to 18m long; standing water; also re- 

 ported 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 questionable genus; 

 fresh water. 



