The narrow whorlsnail Vertigo angustior in the Netherlands (Mollusca: Gastropoda) In June and July 2001, a special survey was held in several coastal areas in the province of Zuid- Holland, the Netherlands. The main objective was retrieving additional data on the occurrence of Vertigo angustior Jeffreys, 1830 in this part of the Netherlands. This very small (<2 mm) terrestrial mollusc is placed in Annex ii of the Habitat Directive. In total 58 sites, distributed over 37 kilometer squares were visited. Vertigo angustior was found at 12 sites, in 10 kilometer squares. It was found near the Maasvlakte (2 populations, near the Brielse Gatdam), at the island of Voorne (4 populations), near Meijendel (1), near Berkheide (1), in the dunereserve Amsterdamse Waterleidingduinen (2). The species was not found near Arensduin/Banken. At the island of Goeree no living specimens could be found, just empty shells (at 2 localities).