Cyclopyxis pirini Golemansky, 1974

Diagnosis. In ventral view, the shell is circular, in lateral view, it is low hemispherical with a more or less sharp edge between the dome and the ventral side. The aperture is at the end of an invagination of the ventral side and is about 1/2 of the test diameter. Shell embedded with mineral grains and diatom frustules.

Dimensions: According to Golemansky (1974): Shell diameter 237—325 µm; height 140—160 µm; aperture 137—168 µm.

Habitat: Sphagnum and soil mosses.

Geographical distribution: Lake Popova, Bulgaria.

Remarks: The only species that resembles C. pirini is C.penardi which is larger (diameter 330—380 µm).