The study of the anatomy of Euomphalia aristata from the Western Transcaucasia showed that these populations differ from other species of the genus and from the typical populations of E. aristata from the North Caucasus in anatomy of the genitalia. E. aristata in Transcaucasia is characterized by the separation of the distal parts of the male and female sections of the reproductive system, a long oviduct, a very short proximal part of the vagina, and the location of the vaginal appendages close to the mucous glands. In E. aristata from the North Caucasus (North Ossetia), the male and female parts of the genitals are not separated in the distal part, the oviduct is short, the proximal part of the vagina has an S-shaped bend, and the vaginal appendages are located at a noticeable distance from the mucous glands. On these grounds we distinguish E. aristata in Transcaucasia as a separate species.
E. aristata was described from the vicinities of Kislovodsk that is on the northern macro-slope of the Main Caucasian Ridge; therefore, the name E. aristata is applicable to the snails inhabiting this region. For molluscs living on the southern slopes of the Caucasus Range and further south, we propose the name Euomphalia schileykoi sp. nov.
