Genus: Arrangement of 4 daughter cells flat and rectangular in shape, forming composite coenobium; without gelatinous sheaths, no hairly projections (Illustrations of the Japanese Freshwater Algae, 1977). Species: Colonies circular in outline, with a small rectangular space at the center; cell body nearly spherical or triangular, 3-7 μm long, 3-6 μm wide; chloroplasts 1-4, parietal disciform, with a pyrenoid (Photomicrographs of the Freshwater Algae, vol. 3, 1985).

31 μm 63 μm 94 μm; x 640