Species[ var. logiense]: Cell body slightly longer than width, 59-65 μm long, 48-53 μm wide, isthmus 16-22.4 μm wide; semicells reniform, basal corners rounded, with 2 pyrenoids. [f. expansa]: Cell body slightly longer than width, 64.4-67 μm long, 50.4-53 μm wide, isthmus 16.8-18 μm wide; semicells reniform, basal corners rounded, apex broader than that of var. logiense; cell wall covered with many granules (Illustrations of The Japanese Fresh-water Algae, 1977).

31 μm 63 μm 94 μm; x 640