Vertigo genesii

Vertigo genesii, common name the round-mouthed whorl snail, is a species of minute air-breathing land snail, a terrestrial pulmonate gastropod mollusc or micromollusc in the family Vertiginidae, the whorl snails.



Shell description
The shell is very small, ovate, obtuse, indistinctly, spaced striate, glossy purplish brown. The shell has 4½ whorls, that are rather convex, high, rapidly increasing, joined by a somewhat impressed suture, the penult large, almost ventricose. Umbilical opening is moderate.

The aperture is semirotund, nearly quadratic, without any folds. Peristome is scarcely expanded, thickened liplike, bordered with bluish black, the margins are connected by a very weak callus, the right margin is arched at the insertion.

The width of the adult shell is 1.03–1.20 mm, the height is 1.63–2.00 mm.

Anatomy
The animal body color is raven-black. The tentacles are short, contracted in the middle.

Distribution and conservation status
This species occurs in:
 * IUCN red list - conservation dependent
 * It is mentioned in Annex II of the European Union's Habitats Directive.
 * British Isles (in the United Kingdom only): Great Britain. It is endangered in Great Britain and it is listed in List of endangered species in the British Isles.
 * Continental Europe: Finland, Germany, Norway, Poland, Romania, Russian Federation, Sweden, and Switzerland.