Een voorlopig overzicht van de malacofauna van de fortificaties van de Stelling van Amsterdam in Noord-Holland

Several fortifications belonging to the “Stelling van Amsterdam” (“Defence Line of Amsterdam”) were visited in order to investigate the presence of terrestrial and freshwater snails and mussels. In this article we present all the data which have been collected so far. We have the intention to carry out additional surveys on all the fortifications belonging to the “Stelling van Amsterdam”, the latter has been placed on the World Heritage List of the UNESCO in 1996. We experienced that it is not always easy to get permission to visit the fortifications in order to carry out zoological research. This article is written in order to stimulate further interest for such surveys.