Species [ var. angulosum ]: Cell body small, 14-31 μm long, 12.6-21 μm wide,
L/W=1.5, isthmus 3.4-6 μm wide; semicells quadrate or hexagonal in shape. [ var. concinnum ]: Smaller than var. angulosum, (11-12)-13 μm long, 8-12 μm wide, L/W=1.3, isthmus 2.6-4.5 μm wide (Illustrations of the Fresh-water Algae, 1977). |