Genus: Cells are equal in size (Illustrations of The Japanese Fresh-water Algae, 1977). Planktonic; colony within a gelatinous sheath; cell body spherical, elliptical or pear-shaped; 4 daughter cells attached to a filament dichotomously radiating from the center of the colony; a single chloroplast cup-shaped, with a pyrenoid. Species: Cell body ovoid, 4-10 μm long, 3-7 μm wide, attached by their longer sides to radially, dichotomously branched filaments; chloroplasts single, cup-shaped, with a pyrenoid (Photomicrographs of the Freshwater Algae, vol. 1, 1984).

Similar genus -->> Planktosphaeria; Westella;

31 μm 63 μm 94 μm; x 640

D. ehrenbergianum Nägeli: Cell body ovoid, 4-10 μm long, 3-7 μm wide, attached by their longer sides to radially, dichotomously branched filaments; chloroplasts single, cup-shaped, with a pyrenoid (Photomicrographs of the Freshwater Algae, vol. 1, 1984).