Genus: Test ovate, discoid in cross-section; pseudostome a terminal slit (Illustrated Guide, 1985). Species: Test chitinous, transparent, yellowish; frontal view oblong-oval or pyriform, 110-140 μm long; a minute pore present on each side at the broadest point; lateral view elongate-pyriform; pseudostome forming a shallow notch; transverse section narrowly elliptic; (Cash, The British Freshwater Rhizopoda and Heliozoa vol. II, 1909).

31 μm 63 μm 94 μm; x 640

Images of collecting locality: No.5, Ryugahara marsh, Chokai mountain, Yuri-Honjo city, Akita Pref., Japan, September 29, 2008 by Y. Tsukii