Protoplagiopyxis ridderae Chardez, 1969

Diagnosis: Shell dark brown, circular in dorsal view, in lateral section the shell is oval, with a ventral area slightly less rounded than the dorsal area. The pseudostome is narrow arranged in an arc of a circle with regular edges. The ventral lip is very slightly folded inwards. Thick chitinoid coating with some exogenous quartz elements.

Habitat: Soil.

Dimensions: length 60-65 µm, height 28-30 µm.