Genus: Colonies small, spherical or aggregates in shape; sheath inconspicuous or absent; cell body spherical in shape;
chloroplasts cup-shaped or plate-like (Illustrations of the Japanese fresh-water algae, 1977).
Sphaerocystis sp. ?,
cell body nearly spherical, 8-11 μm in diam.,
x 640, Hakama marsh (or bog), Madarao highland (Niigata & Nagano Pref.), Myoko village, Niigata Pref., Japan, May 15, 2005 by Y. Tsukii
94 μm; x 640