Argynnia circulata (Bartos, 1963) comb. nov.
Basionym: Nebela circulatea Bartos, 1963

Diagnosis: Shell pyriform in frontal view, in lateral view very flattened and rounded at the fundus. Surface covered with small, circular plates at the front and with strikingly large, circular plates at the back. The plates are spaced widely apart from one another and are glued into the putty mass, and in the spaces between them there are an extraordinary number of extremely small, round plates. Shell embedded with a series of closely spaced, regularly square or irregularly polygonal plates at the edge of the shell opening, which form a smooth or jagged mouth edge at the front and are clearly set off from the plates on the rest of the shell surface, forming a collar.

Dimensions According to Bartos (1963): Shell length 122 µm; width 70 µm; thickness 34 µm; aperture 30 µm long and 15 µm wide; collar 4 µm wide.

Habitat: Moss.