Chilostoma adelozona

The shell is broadly tumid—bulging in profile—and measures 16–29 mm across with a height of about 14 mm. It has 4–5 slightly convex whorls (the spiral turns of the shell) separated by a clear suture, and a wide, off-centre umbilicus (the hollow at the shell's base). The overall hue is pale horn-coloured, usually with a faint brown band around the periphery and a paler zone immediately beneath. The aperture (shell opening) is set obliquely and is edged by a white, reflected lip. Populations of the nominotypical subspecies occur mainly on calcareous cliffs between Lake Lugano and Brescia, whereas C. adelozona rhaeticum inhabits talus slopes under heavy boulders—often non-calcareous—in eastern Alpine localities such as Valtellina, around 1,500 metres elevation. Shell form and banding can vary considerably with geography and microhabitat.^[3]

Chilostoma adelozona is native to the southern Alps of northern Italy (particularly Lombardy and Alto Adige) and adjacent areas of Switzerland. It favours montane rock habitats—vertical or overhanging faces, rocky outcrops and scree—at elevations from about 1,500 m up to 1,800 m. Moisture for this snail is supplied by seepage from snowmelt and persistent damp crevices, making these cool, shaded rock environments essential for its survival.^[3]