Euxina is a genus of land snails in the family Clausiliidae. The name of the genus, derived from Pontus Euxinus, the classical name name of the Black Sea, hints at the genus's distribution range mostly along the coasts of the Black Sea. Three species have been recorded in and around Istanbul, Turkey. Two of them, E. hetaera and E. circumdata, are among the snail subjects of a manuscript I have been working on.
The 2 species have similar shells that may be somewhat difficult to tell apart unless one has specimens of both available for comparison.
The shells of E. hetaera are usually larger than those of E. circumdata. The former also has denser ribs on the ventral side of the body whorl (above the aperture). These characteristics are obvious in the above picture where the pair on the left is E. circumdata and the one on the right is E. hetaera.
The 2 species seem to live in similar if not identical habitats and their colonies may sometimes be found near each other, although I don't know if I have ever found them together.
Here is a live E. circumdata. Note the length of the foot relative to that of the shell. That may be the subject of another post.
The previous entry in the land snails of Turkey series was Paramastus spratti.