Aanvullende gegevens betreffende de weekdierfauna van de inundatiesluis behorend tot de Stelling van Amsterdam in de Beemster

In the autumn of 2012 a follow-up malacological survey was carried out in the area belonging to the inundation sluice of the Beemster, province of North-Holland, the Netherlands. This sluice formed part of the so-called 'Defence Line of Amsterdam'. In addition to the former inventory seven species could be registered: Carychium tridentatum, Succinea putris, Vertigo antivertigo, Vertigo pygmaea, Vitrea contracta, Mila:x nigricans and Boettgerilla pallens. With these additions, 30 species are now known from this former military installation. Except for the amphibious Galba truncatula thus far aquatic molluscs could not be collected due to problems related to the ownership of the non-public part of this area.