Genus: Individuals clustered at end of a simple or branching stalk; fresh water (Kudo, 1966). Cells lacks periplast; collar well developed surrounding a single anterior flagellum; 2 or more posterior contractile vacuoles (Illustrated Guide, 1985). Species: Cell body 8-30 μm long, cysts with thick wall (Starmach, 1985).

31 μm 63 μm 94 μm; x 640

Images of collecting locality: Fujimi-hotaru-shinsui Park, Okegawa city, Saitama Pref., Japan, January 29, 2006 by Y. Tsukii