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 Species: Cell body elongated spindle-shaped, μm long, μm wide, L/W= ;

31 μm 63 μm 94 μm; x 640

Images of collecting locality: No. 1, Iroha-numa (marsh/bog), Zao mountain, Yamagata city, Yamagata Pref., Japan, August 2, 2006 by Y. Tsukii