Order & Family: Floating unicells or a colony embedded in a matrix; no differentiation of apical and base structures; only one family. Genus: Unicells or a colony of spherical cells covered with a distinct sheath (Illustrations of The Japanese Fresh-water Algae, 1977). Cells spherical or ellipsoidal, hemispherical after division, eclosed by the individual sheath (Photomicrographs of the Freshwater Algae, vol. 3, 1985). Species: Cells bright blue-green, sometimes coarsely granulated, 8-32 μm in diam. (without sheath), sheaths 2-6 μm in thickness (Photomicrographs of the Freshwater Algae, vol. 3, 1985).

31 μm 63 μm 94 μm; x 640