Spumochlamys perforata Kudryavtsev, Pawlowski and Hausmann, 2009

Diagnosis: Shell with a flexible aperture, which may open as wide as ca 0.3—0.8 times the test diameter (average 0.6) depending on the physiological condition of the cell. The dorsal part of the test wall consists of irregular alveoles;  test surface uneven, with numerous pores; single vesicular nucleus; central nucleolus.

Dimensions: According to Kudryavtsev et al. (2009): Shell diameter 36—61 µm (mean 45 µm); diameter of aperture 12—39 µm (average 26 µm) (n = 100);  pores in the test wall ca 0.2—0.9 µm in diam. (average 0.4 µm); nucleus 6—12 µm in diam. (average 9 µm); central nucleolus 4—9 µm in diam. (average 6 µm).

Type habitat. Dry epiphytic moss Dicranum scoparium,

Geographical distribution: North-western Russia.