Family: Colorless body; two flagella, one directed anteriorly and the other usually
posteriorly; stigma absent.
Genus: Oval, flattened, longitudinally striated; anterior flagellum about four times longer than shorter trailing one; fresh or salt water (How to know the protozoa, 1979).
Images of collecting locality:
A small pond near Yamakado marsh (Yamakado-Suigen-no-Mori), Nishi-Azai town, Shiga Pref., Japan, June 30, 2008, by Y. Tsukii