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: lacks arm-like projections (Illustrations of The Japanese Fresh-water Algae, 1977) Species: cell body excluding spines 32-42 μm long, 34-39 μm wide (without spines), constriction 11-167 μm wide, (Illustrations of The Japanese Fresh-water Algae, 1977)

31 μm 63 μm 94 μm; x 640

Images of collecting locality: Block 4, Kashibaru marsh, Karatsu city, Saga Pref., Japan, September 9, 2008 by Y. Tsukii