Vertigo (Vertigo) lilljeborgi (WESTERLUND, 1871)

Shell: Dextrous, whorls 4.0-4.7, most often 4.3-4.4. Shape ovate, from very short to rather elongate, spire tapered. Whorl most often strongly convex, suture deep. Aperture distinctly semicircular. Teeth 1-6: columellar, of variable size and shape; parietal, short and high lamellate; upper and lower palatal; basal and suprapalatal. Umbilicus shallow, closed. Surface sculpture of very delicate, irregular, poorly visible striae. Colour from very light to dark brown, with reddish tint.
Dimensions: Height 1.73-2.05 mm, breadth 1.15-1.33 mm, aperture height 0.48-0.55 mm, aperture breadth 0.63-0.78 mm, body whorl height 1.33-1.28 mm.
Ecology: A stenotopic species very closely associated with open marshes and fens; even in oligotrophic habitats of pH ca. 5 but avoiding decidedly poor conditions; found among flood debris and leaf litter of e.g. willow bushes; also in Sphagnum and brown moss fens.
Distribution: A North-European species; its main distribution area comprises Scandinavia except its northernmost fringes, northern part of England, Ireland; recorded from isolated localities in southern part of Germany and Pyrenees; know to occur in the north-western territories of the European part of Russia. Not recorded from Poland, but because of its occurence in adjacent part of Russia likely to be found there.