This map compares the numbers of known enid species in Europe, the former Soviet Union and Turkey. The species number for Europe is from Fauna Europaea, but excludes the species that are endemic to the Azores, Canary Islands and Cyprus. The species number for the former Soviet Union is from Suvorov1. And the species number for Turkey is from Schütt2 with revisions based on recent papers. All numbers are estimates. The total for Europe is probably inflated, because it contains numerous subspecies, while the Turkish total excludes them. I don’t know how the total for the former Soviet Union was calculated. Also, there are undoubtedly more species to be discovered in Turkey and in the countries of the former Soviet Union. In contrast, most, if not all, European enids are probably already described.
The bottom line is that Turkey has disproportionately more species than either Europe or the former Soviet Union. What does that tell us?
1. Suvorov, A.N. 1998. Snails of one sixth of the world’s dry land (the former
USSR).Tentacle, #8, p.6. pdf
2. Schütt, H., 2001. Die türkischen Landschnecken. Acta Biologica Benrodis, Supplementband 4, 1–549.