Genus: Planktonic; colony of 4 cells; cell body spherical, covered with elongated spiny projections; cells attached with each other arranging cruciform on a plane, with a small space at the center of the colony; a single chloroplast plate-like, with a pyrenoid (Guide book to the "Photomicrographs of the Freshwater Algae", 1998). Species:

31 μm 63 μm 94 μm; x 640