Genus: Unicellular; variable in shape; a constriction at the center of the cell body; mostly longer than wide; flattened; each semicell hemispherical, spherical, ellipsoidal, rectangular, pyramidal or kidney-shaped; no apical indentation (Illustrations of The Japanese Fresh-water Algae, 1977). Species: Cell body small, 8.5-13 μm long, 7-12 μm wide, isthmus 2.8-4.3 μm wide; (Illustrations of the Japanese Fresh-water Algae, 1977).

Similar species -- >> C. norimbergense;

31 μm 63 μm 94 μm; x 640

Cosmarium succisum W. et G.S. West var. succisum: Cell body small, 8.5-13 μm long, 7-12 μm wide, isthmus 2.8-4.3 μm wide; (Illustrations of the Japanese Fresh-water Algae, 1977).