Genus: Cell body usuall large, spindle or cylindroid in shape, rounded at both ends; two chloroplasts star-shaped at cross-section, consisting of a central rod and radially arranged dented laminae (Illustrations of The Japanese Fresh-water Algae, 1977).
Species: Cell body 140-380 μm long, 40-80 μm wide, L/W = 2.5-4; cell wall smooth; chloroplasts with 5-6 ridges (Photomicrographs of the Fresh-water Algae, 1984).