Species: Trichome straight, gradually attenulated toward ends, 2.7-4.5 μm long, 5.5-9 μm wide, L/W=1/3 (0.3); septum constricted; terminal cells conical (Illustrations of The Japanese Fresh-water Algae, 1977).

31 μm 63 μm 94 μm; x 640

Images of collecting locality: No. 2, Teganuma Biotope, Abiko city, Chiba Pref., Japan, February 17, 2008 by Y. Tsukii