Cyclopyxis arenata (Cushman, 1930) Boltovskoy, 1956
Basionym: Pseudarcella arenata Cushman, 1930
Diagnosis: Hemispherical shell. Convex dorsal side, ventral somewhat concave in its middle part. Rounded aperture, located in the center of the ventral side. Agglutinated walls, covered with medium-sized sand grains. Color from white to ocher.
Dimensions: Diameter NA.
Ecology: Freshwater. Rio Grande, Ushuaia, Patagonia.