Truncatellina costulata (NILSSON, 1822)

Shell: Dextrous, whorls 5.2-6.2. Shape cylindrical, from short to elongate. Whorls moderately to strongly convex, suture moderately deep to deep. Aperture almost completely circular. Teeth 3: columellar, knob-shaped; parietal, low short and thick lamellate; palatal, knob-shaped or roll-like. Umbilicus deep, open. Surface sculpture of strong, prominent, regular ribs. Colour from horny-yellowish to light goldish-brown, teeth white.
Dimensions: Height 1.60-1.95 mm, breadth 0.80-0.90 mm, aperture height 0.50-0.60 mm, aperture breadth 0.53-0.63 mm, body whorl height 0.85-1.00 mm.
Ecology: Living in dry habitats: dry grassland on calcareous substrate, sand dunes, open woodlands. In Poland roadside sunny tree stands and dry shrubs; found among plant debris.
Distribution: A Central- and Eastern-European species: in the north to Denmark, southern Sweden, Rugen; in the south and west to Germany and Austria; in the east southern part of the Russia, Caucasus, Esthonia. In Poland recorded from the Pomeranian and Mazurian Lake Districts and Wielkopolsko-Kujawska Lowland.