Landslakken langs spoordijken 4. Landslakken langs het traject Purmerend-Hoorn

The railroadtrack from Purmerend to Hoorn, covering some 32 km, was investigated at 12 localities for the presence of terrestrial snails in the autumn of 2001 (with some minor observations carried out in the autumns of 1998 and 2002). The presence of at least 37 species could be established. Part of the material belongs to the original wetland malacofauna of Noord-Holland, but others like Monacha cantiana, Candidula intersecta, Cernuella virgata and Cernuella cisalpina, are species usually found in dry habitats. Most interesting were the first finds of Deroceras panormitanum, Hygromia cinctella and Helix pomatia in that part of Noord-Holland. This railway embankment functions as a dry island and excellent biotope for xerothermic species, in an otherwise extremely wet area.