Vertigo (Vertigo) geyeri LINDHOLM, 1925

Shell: Dextrous, whorls 4.0-4.6, most often 4.5. Shape short ovate, spire tapered. Whorls strongly convex, suture deep; rarely whorls moderately convex and suture moderately deep. Aperture nearly semicircular. Teeth 4, only exceptionally 3: columellar, fold-like or knob-shaped; parietal, short and high lamellate; lower and upper palatal. Umbilicus shallow, closed. Surface sculpture of extremely delicate, regular striae. Colour reddish-brown of varying intensity, teeth lighter.
Dimensions: Height 1.63-1.93 mm, breadth 1.05-1.20 mm, aperture height 0.43-0.48 mm, aperture breadth 0.58-0.70 mm, body whorl height 1.00-1.15 mm.
Ecology: A calciphile like V. genesii: calcareous fens near water bodies of a rather stable water level and of mesotrophic type; found among plant debris and in tufts of vegetation.
Distribution: A Boreo-Alpine species: mostly Scandinavia where its distribution border passes probably between 60° and 62°; north-western part of Russia, British Isles and Czech and Slovak Republic. Recorded from the vicinity of Bialowieza, on the territory belonging at present to the Belarous. Because of its occurence in adjacent areas the species is likely to be found in Poland.