Tetraedron caudatum
(Corda) Hansgirg var. incisum Lagerheim
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).
Species [ var. incisum ]: