Species: Colonies linear filaments consisting of 10-20 cells; cell body short cylindroid, both ends rounded, 15-20 μm long, 8-10 μm in diam.; cells separated each other; a single chloroplast plate-like, with a pyrenoid (Illustrations of the Japanease Freshwater Algae, 1977). The thickness of the gelatinous sheath variable; planktonic; cell body ellipsoidal or cylindrical with rounded ends, 25-35 μm long, 9-20 μm in diam.; cells scarcely adherent to each other or equally separated on another; chloroplasts a single, plate-like forming a girdle, with a pyrenoid (Photomicrographs of the Fresh-water Algae, vol. 3 (1985).

31 μm 63 μm 94 μm; x 640

Images of collecting locality: a small marsh pond near memorial pole of Saito Mokichi (close to Iroha-numa), Zao mountain, Yamagata city, Yamagata Pref., Japan, August 2, 2006 by Y. Tsukii