Gasteropodi terrestri e di acqua dolce dell’area urbana ed extraurbana di Sassari (Sardegna nord-occidentale)

[Terrestrial and freshwater gastropods from the urban and extra-urban area of Sassari (North-Western Sardinia)] Collections and observations relating to the terrestrial malacofauna were carried out of the urban area of the municipality of Sassari, limited only to shelled gastropods. The research, conducted informally, highlighted the presence of 25 species. These results were compared with the findings from research carried out, in the same period and with the same methods, in the non-urban area of the municipality and with the data present in the literature.