Genus: Test variable, chitinoid; binucleate (Illustrated Guide, 1985). Group: Discoides (Test flattened; height < 1/2 greatest diam.) Species:

31 μm 63 μm 94 μm; x 640

Images of collecting locality: Yoshi-numa (a pond) near Ohnuma enchi, Nasu-shiobara city (formerly Shiobara town), Tochigi Pref., Japan, May 5, 2006, by Y. Tsukii