Earlier in the summer while visiting Turkey, I found these snails at 2 widely separated locations. The 1st location was a rocky beach at the coast of the Aegean Sea west of Izmir; the 2nd location was a rocky spot at the coast of the Black Sea north of Istanbul. Because I wasn't familiar with them, I sent their photos to Henk Mienis who identified them as Melarhaphe neritoides.
This is a widespread species in the family Littorinidae. They always live at the edge of the sea sometimes at spots that get wet only occasionally. The snails from the Aegean were on the underside of a rock that was in contact with water, but the ones from the Black Sea were in the cracks of the rocks several meters away from the edge of the sea.
The shell shape of Melarhaphe neritoides appears to be quite variable. Compare the shells of the specimens from the Aegean and the Black Sea.