Species: Cell body cylindrical, large in size, slightly constricted at the center, bands present, 77-325 μm long, 15-30 μm wide, L/W=5-10; cell wall brownish, striated (striae slighlty slanted) (Illustrations of The Japanese Fresh-water Algae, 1977).

31 μm 63 μm 94 μm; x 640

Images of collecting locality: a pond near the entrance of climbing route to Omine mountain, Minakami town (formerly Tsukiyono town), Gunma Pref., Japan, May 25, 2006 by Y. Tsukii