Plagiopyxis lithophora (Bonnet, 1974) Meisterfeld, 2008
Basionym: Bullinularia lithophora Bonnet, 1974

Diagnosis: Shell colorless or yellowish with simple cryptostome. Shape in dorsal view elliptical with axis in the antero-posterior direction. In side view parallel to the long axis, outline more or less semicircular. In ventral view pseudostome situated eccentrically, in a well marked depression. Aperture relatively large with very irregular stony edge. Dorsal lip sometimes with a kind of thickened tooth-shaped pronouncement, composed as the rest of the test. Ventral lip deflecting deeply within the test and having, in frontal view, the shape of a tongue with a rounded edge. Shell covered with quartz particles, sometimes pretty large. Gaps between the xenosomes filled with a yellowish cement, Elements larger toward the center of the ventral side than on the rest of the test.

Dimensions: Length, average 199 µm; width, average 166 µm (n=14).

Ecology: Soils rich in organic debris, backwaters of forest.