Species: 20-35 μm long, 5-10 μm wide; spindle-form with bluntly pointed anterior and sharply attenuated posterior end; a few chloroplasts (Kudo, 1966). 2 leaf-like chloroplasts (Illustrations of The Japanese Fresh-water Algae, 1977). Cell body fusiform, 21-32 μm long, 8-11 μm wide; anterior rounded, posterior bluntly pointed or rounded; 2-3 chloroplasts large, saucer-shaped with slightly lobed margins, 15-24 μm in diam., each containing a pyrenoid covered on both sides by a watchglass-shaped sheath of paramylon; nucleus 6 μm in diam. located posterior; flagellum 1-1.5 body length; stigma (eyespot) 3-4 μm long; muciferous bodies small, spherical; paramylon granules small, oval or elliptiocal (Phtomicrog. Fresh-w. Alg. 9: 37, 1989).