Genus: Cell body short, radiate in shape; apical view of the cell, triangular, polygonal,
ellipsoidal or spindle-shaped; zygospores formed outside of mother cells
(Illustrations of The Japanese Fresh-water Algae, 1977).
Species: Unicells, planktonic; cell body flat, triangular in shape, (6-) 9-14 μm long; laterally concave or convex, ellipsoid in lateral view; angles rounded (sometimes with a knob-like small projections); cell wall covered with small granules (Photomicrographs of the Freshwater Algae, vol. 5, 1986).