|  Genus: Colonies spherical, with inner empty space; cells attached to each other by a protrusion of 
cell wall, arranged in a single layer; cell body mostly spherical with some conical or grobular 
bulges; chloroplasts cup-shaped with a pyrenoid; reproduction by asexual coenobium 
(Illustrations of The Japanese Fresh-water Algae, 1977). Species:
 
 |