Genus: Two flagella of equal length inserted close together into an anterior papilla of variable shape usually directed anteriorly; chloroplast form variable; usually 2 contractile vacuoles; cell division producing 2-8 zoospores; sexual reproduction usually isogamous, anisogamy and oogamy known but rare; > 500 species, mostly fresh water (Illustrated Guide, 1985). A large chloroplast; stigma; a single nucleus; two contractile vacuoles anterior (Kudo, 1966). Species: Cell body ellipsoid or nearly spherical, 5-8 μm long (Süßwasserflora von Mitteleuropa 9, Chlorophyta I, 1983).

31 μm 63 μm 94 μm; x 640