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).
Plagiophrys sp. (Claparéde & Lachmann, 1858), emend Penard,
test 45 μm long, 25 μm wide, pseudostome μm wide,
x 400, x 640, Riverside green land (near Tone river), Sawara city, Chiba Pref., Japan, October 11, 2004 by Y. Tsukii
31 μm 63 μm 94 μm; x 640
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).