Cyclopyxis humilis Bonnet, 1962

Diagnosis: Very small test, clear yellow‑ochre, with a general appearance that in dorsal view resembles Phryganella acropodia. However, in lateral view, the ventral surface appears sharply inflected and connects almost angularly to the sides of the test, though without forming an angle as pronounced as that of Cyclopyxis kahli Defl. In ventral view, the pseudostome is reduced, almost circular, and has a fairly regular outline. The shell is transparent, embedded with fine quartz particles separated by finely punctured cement; sometimes with diatom debris.

Dimensions: According to Bonnet (1962): Shell diameter 40–45 µm; height 38–40 µm; pseudostome 10–12 µm.

Ecology: Soil.

Geographical distribution: Near Lagune de Francisco Moreno, Patagonia, South-America.

Remarks: Due to its size, this species may at first glance be mistaken for Cyclopyxis arcelloides var. gibbosa and Cyclopyxis arcelloides var. ghesquierei. It can be distinguished from these two by the size of the pseudostome and the shape of the ventral surface.