Schoenbornia smithi Beyens & Chardez, 1997

Diagnosis: Shell oval, circular in cross-section. Pseudostome with short circular collar, bordered by irregularly formed mineral particles. Shell wall composed of a thick organic layer, embedded with polymorphic inorganic particles. Shell hyaline or yellow. Cysts spherical and thick-walled.

Dimensions: Beyens and Chardez (1997): Shell length 37-40 µm, width 26-30 µm, aperture 15-18 µm (n=10), cyst 26 µm (n=1). Łuców et al. (2024): Length 41-60 µm, width 26-39 µm, aperture 12-20 µm (n=63).

Ecology: Freshwater, wet mosses. Spitsbergen (Beyens and Chardez, 199); Mongolia (Łuców et al., 2024; Russia, Siberia (Kurina and Barashko, 2020; Preis et al., 2011; Kurina, 2011; Kurina et al., 2020).