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: Cell body 67-75.6 μm long (excluding spines), 84 μm (including spines), 67-92 μm wide, isthmus 16.8-19.5 μm wide (Illustrations of The Japanese Fresh-water Algae, 1977)

31 μm 63 μm 94 μm; x 640

Images of collecting locality: Maimeno-ike (pond), Norikura highland, Azumi, Matsumoto city (formerly Azumi village), Nagano Pref., Japan, June 8, 2006 by Y. Tsukii