Genus: Cell body flat, constricted at the center; semicell with 2 or 4 thick spiny projections; cells attached with each other at the center of their apex forming a filament, spiny projections extending over the adjoining cell. Species: Filaments twisted; cell body 11-12.6 μm long, 11-14 μm wide, constriction 3-5.6 μm wide; semicells ellipsoidal or reniform; apex flat, from both corners two long projections arising to connect with adjoining cell (Illustrations of The Japanese Fresh-water Algae, 1977).

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