Genus: Pseudostome lacks lobed collar; test round or oval in cross-section;
with or lacking a collar (Illustrated Guide, 1985).
Species: Test pyriform, flask-shaped, or ovoid; neck variable in length;
aperture terminal, typically circular; test composed of angular sand-grains, diatoms;
60-580 μm by 40-240 μm (Kudo, 1966).
Difflugia oblonga Ehrenberg,
test 135 μm long, 70 μm wide, L/W=1.9, pseudostome 28 μm wide,
x 200, x 400, x 640, No.4, Tanohara marsh, Shiga highland, Yamanouchi town, Nagano Pref., Japan, June 17, 2007 by Y. Tsukii 31 μm
63 μm
94 μm; x 640
Images of collecting locality:
No.4, Tanohara marsh, Shiga highland, Yamanouchi town, Nagano Pref., Japan, June 17, 2007 by Y. Tsukii