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: Cell body oblong cylindrical with rounded ends, outer cells slightly convex, with short curved spines at both ends, inner cells with short spine-like structures at one end, 7-19 (-22) μm long, 3-9 μm wide; cells contacting with about 80% of lateral walls; cell wall smooth; outer thin cell-wall layer visible between the cell poles

50 μm 100 μm 150 μm; x 400 : 31 μm 63 μm 94 μm; x 640

Scenedesmus curvatocornis Prooskina-Lavrenko curvatocornis: Cell body oblong cylindrical with rounded ends, outer cells slightly convex, with short curved spines at both ends, inner cells with short spine-like structures at one end, 7-19 (-22) μm long, 3-9 μm wide; cells contacting with about 80% of lateral walls; cell wall smooth; outer thin cell-wall layer visible between the cell poles (Photomicrographs of the Freshwater Algae, vol. 20, 1998).