|  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 Subgenus [Eucosmarium]: 
Cell body dorso-ventrally compressed, with strong constriction at the center, 
transverse section elliptical or diamond-shaped.
 Section [Quadratiformes]: 
Cell surface smooth; semicells rectangular
(Illustrations of The Japanese Fresh-water Algae, 1977).
 Species:
 |