Overseas Dispersal of Shells of Terrestrial Snails (Gastropoda: Pulmonata) on the Bulgarian Black Sea Coast

Six species of terrestrial snails recorded from the Bulgarian Black Sea coast should be considered accidentally transported as shells from overseas to the territory of Bulgaria. Four species were reported by previous authors on the basis of shells found in marine sediments: Gibbulinopsis interrupta (Reinhardt, 1876) (reported from Bulgaria as Pupilla bogdanovi Urbanski, 1960, and Pupilla valkanovi Urbanski, 1960, which are recognised as junior synonyms of G. interrupta by the present study), Ena nogellii (Roth, 1850), Chondrus tournefortianus (Ferussac, 1821), and Multidentula squalina squalina (Pfeiffer, 1848). Shells of two other species, Scrobifera taurica (Pfeiffer, 1848) and Elia huebneri (Pfeiffer, 1848), are reported for the first time from Bulgaria in this paper. There are no records of living specimens of these species from the Bulgarian Black Sea coast, and we believe that the shells were carried by sea currents and thus reached the Bulgarian seaside. Therefore, these species should not be considered representatives of the fauna of Bulgaria.