Genus: Test circular, ovoid or discoid; pseudostome eccentric, circular or ovoidal; with or without spines (Kudo, 1966). Species: Test 120-150 x 75-100 μm, 60-75 μm in hight, pouch-shaped in oral view, round in lateral, tapered toward anterior; pseudostome 25-30 μm with incurved lips; several similar species (Illustrated Guide, 1985).

31 μm 63 μm 94 μm; x 640

Images of collecting locality: No.5, Shibayachi marsh, Odate city, Akita Pref., Japan, September 22, 2007 by Y. Tsukii