Family: Test usually more or less compressed; pseudostome narrowly oval or slit-like.
Genus: Test more or less flask-shaped, with more or less neck (Illustrated Guide, 1985).
Species:
Argynnia dentistoma (Penard 1890) ?,
test 230 μm long, 120 μm wide, L/W=1.9,
pseudostome 45 μm wide,
x 200, x 400, x 640, No.1, Kuroyachi marsh, Hachimantai, Hachimantai city, Iwate Pref., Japan, August 23, 2007 by Y. Tsukii
31 μm
63 μm
94 μm; x 640