About Helix thessalica O.Boettger, 1886
Helix thessalica is a species of large, air-breathing land snail that is native to Europe. Externally, it is similar to Helix pomatia, but differs in having dark grey penis and vagina. For a long time, this species was considered to be the same species (synonymous) as H. pomatia. The type locality of Helix thessalica is in Thessaly, Greece, which is also the location of the species' southernmost occurrences in Ossa and Pelion. The species is distributed across northern Greece, North Macedonia, Bulgaria, Montenegro, Kosovo, southern and central Serbia, and the Romanian Carpathians. A small portion of its distribution range is located in the Western Carpathians, specifically in central Slovakia and Bükk in Hungary; in Czechia, it only inhabits a restricted area in the valleys of the Jihlava and Oslava rivers. East of the Carpathians, H. thessalica occurs in Moldova, Ukraine (where it is scattered from the Podolian Upland north to Kharkiv), and Russia (where it is found in Belgorod oblast near Valuyki; a possibly introduced population is recorded from Ulyanovsk).
