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).
Images of collecting locality:
No.5, Kashibaru marsh, Karatsu city, Saga Pref., Japan, November 22, 2006 by Y. Tsukii