Cyclopyxis impressa (Daday, 1905) Da Cunha, 1913
Difflugia lobostoma var. impressa Daday, 1905
Diagnosis: Shell in dorsal view circular, in side view it resembles a somewhat flattened hemisphere; the dorsal side is a bit bulbous; the ventral side is flat with a funnel-like invagination with the aperture. At the outer edge of the funnel is a more or less horizontal brim whose width is 1/3 or 1/4 of the whole shell diameter. The aperture is surrounded with 6-8 pointed chitinous teeth, dark brown or blackish gray, separated from each other by curves. Test embedded with mineral grains and particles.
Dimensions: Shell diameter 300-450 µm, height 100-150 µm; diameter of the funnel 150-190 µm.
Ecology: Freshwater. South-America (Asuncion, Lagoon (Pasito), inundations of the Paraguay River; Sapucay, Arroyo Pona, inundations of a stream; Tebicuay, pond.)