Genus: Unicellular; planktonic; cell body nearly spherical, with 3-4 corners, from which transparent conical projections emerging; 1 or several chloroplasts plate-like, with a pyrenoid (Guide book to the "Photomicrographs of the Freshwater Algae", 1998). Species:

31 μm 63 μm 94 μm; x 640

Images of collecting locality: Kaji-ike park, Abiko city, Chiba Pref., Japan, February 17, 2008 by Y. Tsukii