Species: Cell body cylindrical or ellipsoidal, tapered to both ends, 35-79 μm long, (16-21)-36 μm wide; both ends broadly rounded; cell wall thin, brownish in color, finely lined (15-18/10 μ) (Illustrations of The Japanese Fresh-water Algae, 1977).

31 μm 63 μm 94 μm; x 640

Images of collecting locality: a wetland at Ichinose-enchi, Norikura highland, Azumi, Matsumoto city (formerly Azumi village), Nagano Pref., Japan, June 8, 2006 by Y. Tsukii