Cryptodifflugia compressa Penard,1902
Diagnosis: Shell broad ovoid to circular, compressed in cross section, hyaline, usually yellow brown, younger shells colorless; aperture circular or elliptical, with short collar; few pseudopodia, often tapering to the end; nucleus vesicular.
Dimensions: Literature L 13-36 µm, B 9-36 µm.
Ecology: Freshwater, mainly on waterplants, but also between Sphagnum and in detritus. Locally sometimes very common.