Arcella oyei Stepanek, 1963
Diagnosis: In dorsal view, the shell is circular, with 10 apparent broken lobes on the surface. In lateral view, the shell is not high and is bent like the hat of a mushroom. The edge of the aperture is deeply sunken and around the opening is a small socket that is bent back into the inside of the shell. On the surface of the shell are 10 radially protruding ribs, between which there are lobe dimples, which however merge with the ribs and with the shell surface on its neck and at the edges. The shell color is yellowish, the walls are weak with a hardly noticeable structure of a typical shape for the genus.
Dimensions: Diameter 42 µm, height 15 µm, aperture 14 µm.
Ecology: Freshwater. Central Africa.