Sphenoderia australis Playfair, 1917

Diagnosis: Shell very broad oval or subglobose, very slightly compressed or not at all, broadly rounded behind; sides strongly curved, converging towards the opening. Opening just a slit at the top of a structureless collar. Body scales of different sizes and shapes in the same test, and without any regular arrangement, slightly overlapping each other. Side view oval.

Dimensions: Length 57-70 µm; width 32-60 µm; collar 17-28 µm; 5-6 µm high.

Habitat: Freshwater. Australia.

Remarks: Playfair (1917): “This species is sufficiently distinguished from Sphenoderia lenta by the irregular arrangement of the scales and their varying size and shape. At their best they tend to be circular.”