Genus: Body colorless; plastic; flask-shaped; striated; a funnel-like neck; posterior region stout; a single flagellum protruded from funnel and reaches inward the posterior third of body (Kudo, 1966). Species: 25-50 μm long; fresh water (Kudo, 1960; How to know the protozoa, 1979).

31 μm 63 μm 94 μm; x 640

Images of collecting locality: No.1, Ryugahara marsh, Chokai mountain, Yuri-Honjo city, Akita Pref., Japan, September 29, 2008 by Y. Tsukii