Truncatellina claustralis (GREDLER, 1856)

Shell: Dextrous, whorls 5.5-6.8. Shape cylindrical, from short to elongate. Whorls moderately to strongly convex, suture moderately deep to deep. Aperture semi-oval. Teeth 3: columellar; parietal, low and thick lamellate; palatal, knob-shaped or roll-like. Umbilicus deep, open. Surface sculpture of delicate, distinct, regular ribs, spaced closer than in T. costulata. Colour from horny-yellowish to light goldish-brown, teeth white.
Dimensions: Height 1.60-1.85 mm, breadth 0.70-0.79 mm, aperture height 0.35-0.49 mm, aperture breadth 0.40-0.53 mm, body whorl height 0.68-0.80 mm.
Ecology: A xero- and thermophile, associated with calcium-rich substrates; dry, sunny limestone hills, limestone screes and dry, sparse deciduous forests.
Distribution: A Mediterranean species: a part of southern Europe from southern France to Crimea, with many large gaps in its distribution range; isolated localities in the Northern Alps and Czechoslovakia. In Poland one locality on the Wawel Hill in Cracow, another in the vivinity of Ojcow, Cracow-Czestochowa Upland, at the latter locality not confirmed recently.