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 constricted near the both ends, (68-160)-288 μm long, (7-8)-10.8 μm wide, L/W = 10-16, cell wall densely granulated (Illustrations of The Japanese Fresh-water Algae, 1977).
Images of collecting locality:
Water reservoir, near Teruoka pasture, Nabekura highland, Iiyama city, Nagano Pref., October 19, 2008, by Y. Tsukii