Genus: Pseudostome lacks lobed collar; test round or oval in cross-section; pseudostome relatively large, with or lacking a collar (Illustrated Guide, 1985). Species: 70-110 μm long; 55-85 μm diam.; test oval, round cross-section; brown, chitinoid, with imbedded siliceous plates, attached debris (Illustrated Guide).

31 μm 63 μm 94 μm; x 640

Images of collecting locality: No. 3, Miyatoko marsh, Minami-Aizu town, Fukushima Pref., Japan, June 15, 2008 by Y. Tsukii