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 (49-61)-78 μm long, (28-39)-45 μm wide, L/W = 1.5, constriction (17-20) μm wide, (Illustrations of The Japanese Fresh-water Algae, 1977).
Images of collecting locality:
Iyari marsh, Omachi city, Nagano Pref., Japan, May 8, 2006 by Y. Tsukii