Genus: Unicellular; variable in shape; a constriction at the center of the cell body;
mostly longer than wide; flattened; each semicell hemispherical, spherical, ellipsoidal,
rectangular, pyramidal or kidney-shaped; no apical indentation
(Illustrations of The Japanese Fresh-water Algae, 1977).
Species: Cell body 20-28 μm long, 19-22.4 μm wide, isthmus 6-8.4 μm wide (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