Genus: Elliptical body with a firm pellicle; dorsal side convex, ventral side slightly flat; "cytopharynx" with granules; two lateral chromatophores (chloroplasts) vary in color from green to blue-green, brown or rarely red; 1-3 contractile vacuoles anterior (Kudo, 1966). Cell body elongated ovoid or elliptical; cytopharynx conspicuous; three rows of ejectisome (trichocysts) (Yamagishi, 1999). Species: Cell body 16-25 μm long, 8-13 μm wide, thickness 7-12 μm; anterior end slanted, posterior end rounded; longitudinal groove extending to near the posterior end; chloroplasts brownish, with 4, 6-7 pyrenoids; starch granules scattered within the chloroplasts; stigma absent; two refractile bodies at the center of the cell (An Illustrated Guide to Freshwater Zooplankton in Japan, 2000).

Similar genus -->> Chroomonas; Chilomonas;

31 μm 63 μm 94 μm; x 640

Images of collecting locality: a small pond near Yoshino park, Mitsukaido city, Ibaraki Pref., Japan, January 24, 2006 by Y. Tsukii