Genus: Trichome without mucous sheath; straight, long, consisting of numerous cells (Illustrations of The Japanese Fresh-water Algae, 1977). Species: Trichome straight, without constriction at cell-cell junction, tapering at both ends, 4-6.5 μm wide; cell body short, 1.5-3 μm long (1/3-1/2 of its width); granules present along septum (Illustrations of the Japanese Fresh-water Algae, 1977).

31 μm 63 μm 94 μm; x 640

Oscillatoria brevis (Kützing) Gomont: Trichome straight, without constriction at cell-cell junction, tapered at terminal end, 4-6.5 μm wide; cell body short, 1.5-3 μm long; small granules arranged at septum (Illustrations of the Japanese Fresh-water Algae, 1977).