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 120 μm long, 108 μm wide, pseudostome μm wide,
x 640, a small wetland near Numa-no-hara marsh (Genseikaen), Madarao highland (Niigata & Nagano Pref.), Myoko village, Niigata Pref., Japan, May 15, 2005 by Y. Tsukii
31 μm
63 μm
94 μm; x 640