Genus (Diesing): Cells obovate or almost spherical, flattened dorsoventrally; rod-shaped trichocysts around cell periphery or concentrated at the 2 ends of the cell; flagella usually same length as cell; but trailing flagellum may reach twice that length; many chloroplasts in a single layer in the cell periphery (Illustrated Guide, 1985). (Illustrations of The Japanese Fresh-water Algae, 1977).
Species: Cell body circular in shape, dorsoventrally flattened, about 35 μm long, 10 μm in thickness; a nucleus ellipsoidal, located at the center of the cell body; many elliptical chloroplasts located at perphery of the cell body; trichocysts uniformly distributed (Illustrations of The Japanese Fresh-water Algae, 1977).