Genus: Unicellular or colonial within a gelatinous sheath; planktonic; cell body spherical;
1 or several chloroplasts cup-shaped, with a pyrenoid
(Guide book to the "Photomicrographs of the Freshwater Algae", 1998).
Similar genus --> Dictyosphaerium Planktosphaeria ?,
cell body spherical, 4-6 μm in diam.,
x 640, a small pond near Yamaguchi university, Yamaguchi city, Yamaguchi Pref., November 21, 2004, by Y. Tsukii
94 μm; x 640