Balea perversa

Balea perversa is widely distributed in western and central Europe east to Ukraine and westernmost Russia:[1] It was referred from Crimea,[3] but it was probably Mentissa gracilicosta.

[3] Balea perversa lives on mosses and at the bark of trees, also near roads, at walls and rocky slopes, at rocks, less commonly in ground litter.

[3] Animals can reach maturity after 3–4 months under favourable conditions, one adult can give birth to 10-20 juveniles per year.

[3] It is locally threatened by too thorough and too frequent restorations of old buildings, acid rains, air pollution and cutting of old trees.

[3] Remains frequent in Ireland, but many colonies in lowland England have certainly disappeared, extinct around London since the 1920s.

shells of Balea perversa
Apertural view.
Lateral view.