Genus: Two chloroplasts plate-like or slightly spiralled; a nucleus centrally located between the chloroplasts; mostly unicells, filaments rare (Illustrations of The Japanese Fresh-water Algae, 1977).
Species: cell body cylindrical 162-(185-230)-236 μm long, 11-(12)-14 μm wide, L/W = 14-25 (or 40), cell wall smooth, both ends not swelled, 2 chloroplasts with 4-10 pyrenoids in each (Illustrations of The Japanese Fresh-water Algae, 1977).