Genus: Cell body short, radiate in shape; apical view of the cell, triangular, polygonal, ellipsoidal or spindle-shaped; zygospores formed outside of mother cells (Illustrations of The Japanese Fresh-water Algae, 1977)
Subgenus: with arm-like projections (Illustrations of The Japanese Fresh-water Algae, 1977)
Species: semicells twisted with each other at isthmus (Illustrations of The Japanese Fresh-water Algae, 1977)