Genus: Test elastic, punctate; pseudostome round;
few plate-like attached particles (Illustrated Guide, 1985).
Envelope (test) thin, hyaline, changeable with body form; usually elongate-oval
with rounded posterior end; narrowed at other half; envelope finely punctated with a few small plates;
aperture round; cytoplasm clear (Kudo, 1966).
Images of collecting locality:
Maimeno-ike (pond), Norikura highland, Azumi, Matsumoto city (formerly Azumi village), Nagano Pref., Japan, June 8, 2006 by Y. Tsukii
Plagiophrys parvipunctata Penard, 1902: Cell body 45-55 μm long, 18-20 μm wide, 10-12 μm thick; test ovoid, clear, flexible; cross section oval, punctate, attached particles; pseudostome round 4-5 μm; nucleus spherical, no endosome (Illustrated guide, 1985).