Genus: Unicellular, planktonic; cell body ovoidal or ellipsoidal; both ends slightly pointed with
4 to 8 spiny projections; a single chloroplast plate-like in shape, with 1 to 4 pyrenoids
(Guide book to the "Photomicrographs of the Freshwater Algae", 1998).
Species: Cell body spherical, (4-)5-10 μm in diam., with 4 long spines 8-18 (-26) μm long; each spine with a small basal nodule; a single chloroplast parietal plate-like, with a pyrenoid (Photomicrographs of the Freshwater Algae, vol. 7, 1987).