Trigonopyxis minuta  Schönborn & Peschke, 1988

Diagnosis: Shell nearly hemispherical, height of shell averaging 65% of shell diameter; aperture central, invaginated, only rarely triangular and rimmed, smaller than that of T. arcula, roughly circular to irregularly oblong; color brownish; xenosomes composed of plain stones and detritus particles. An internal shell exists and is, where the external shell is broken, clearly visible.

Dimensions: According to Schönborn & Peschke (1988): Shell diameter 68.7—87.5 µm (mean 76 µm); height 43.7—56.2 µm (mean 49 µm); aperture 12.5—21.9 µm. My measurements: diameter 50 µm, height 45 µm.

Ecology: Soil, mosses.

Geographical distribution: Reported world-wide.