Vertigo ronnebyensis is a species of small land snail

Snail

Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...

 from the family Vertiginidae

Vertiginidae

Vertiginidae is a family of minute, air-breathing land snails, terrestrial pulmonate gastropod molluscs or micromollusks in the superfamily Pupilloidea.- Distribution :...

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Shell description

Shell

Gastropod shell

The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...

 is deeply perforate, long-ovate, regularly finely striate, very glossy and reddish-brown in color. The shell has 5½ convex whorls

Whorl (mollusc)

A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...

. The last whorl

Body whorl

Body whorl is part of the morphology of a coiled gastropod mollusk.- In gastropods :In gastropods, the body whorl, or last whorl, is the most recently-formed and largest whorl of a spiral or helical shell, terminating in the aperture...

 is about equal to the penult, which is a third higher than the preceding whorl, which is double the height of the next earlier. Last whorl has a transverse callus of the same color near the aperture

Aperture (mollusc)

The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....

. Suture is very oblique, ascending to the aperture.

Aperture is quite obliquely piriform, excised by the very oblique parietal wall. Aperture has 4 teeth: 1 parietal lamella, 1 conic tooth at the lower end of the sharply emerging, dark-colored columella; 2 short, widely separated, deeply immersed palatal folds. Margins are delicately united, the outer margin is weakly arcuate, nearly straight, the columellar margin is broadly reflected.

The width of the adult shell is 1.15-1.35 mm, the height is 2.0-2.35 mm.

Distribution

• Scandinavia: Sweden
• northwestern Russia
• Central Europe: Germany, Czech Republic, Poland