Difflugia microstoma  (Thomas, 1954) Ogden, 1983
Basionym: Difflugia globularis var. microstoma Thomas, 1954

Diagnosis: Penard (1902), on which description Thomas (1954) based his variety, described this species as: “Characterized by a size of 65-70 um, a perfectly spherical shape, a clear chitinoid membrane, but which disappears completely in a tight coating of angular and relatively very large stones. In addition, the mouth always remarkably small barely reached 1/4 of the diameter of the shell.”

Dimensions: Thomas (1954): Length 68—86 µm; aperture 18—23 µm. Penard (1902): Length 65—70 µm. Ogden (1983): Shell length 76—105 µm; width 63—83 µm; aperture 18—29 µm. My measurements: Length about 53 µm.

Habitat: Freshwater. Sediment and in Sphagnum.

Geographical distribution: Europe.