Genus: Colonies of 4 (or 2, 8, 16) cells attached side by side, arranged linearly or zigzag;
cell body elliptical or spindle or crescent in shape; terminal cells with spiny projections in many species;
cell wall usually smooth, but in some species granulated or dented or ridged
(Illustrations of The Japanese Fresh-water Algae, 1977).
Species [ chodatii ]: Colonies of 2, 4, 8 cells, arranging linearly; cell body ovoid or elongated ellipsoidal, both ends rounded, 7-14 μm long, 3-5 μm wide; each cells with longitudinal ridges on both sides, but ridges unclear at the center; outer cells with short spines (2-4 μm long) projecting inward (Illustrations of The Japanese Fresh-water Algae, 1977).