Family: Unicells; cell body spherical or broad ellipsoidal; chloroplasts 1 to several in number, cup-shaped or plate-like, reticulated or star-shaped; with or without pyrenoids; reproduction by autospores and zoospores; many species found in soil (Illustrations of The Japanese Fresh-water Algae, 1977).
Genus: Subaerial algae; cell body without gelatinous coat; a single chloroplast cup-shaped with a pyrenoid (Illustrations of The Japanese Fresh-water Algae, 1977).