Genus: Cell body crescent in shape (long, curved, tapered at both ends); cross section rounded;
cell wall smooth or with longitudinal lines, bands on the cell wall in some species;
chloroplast laminae ridged and radially arranged, which makes cross section star-shaped;
pyrenoids aligned or scattered (Illustrations of The Japanese Fresh-water Algae, 1977).
Species: Cell body 265-380-(400-464) μm long, (39-45)-60 μm wide (Illustrations of The Japanese Fresh-water Algae, 1977).
Images of collecting locality:
No. 3, Iyari marsh, Omachi city, Nagano Pref., Japan, June 1, 2008 by Y. Tsukii