Een aanvullend overzicht van de slakken op en bij het kerkhof van Hoorn op Terschelling, Friesland

The graveyard surrounding the Dutch Reformed Church in Hoorn, Terschelling – a Wadden island belonging to the province of Friesland – is bordered at the eastern and northern edge by a deep trench. Only the northern trench contained some water in which five basommatophoran gastropods were encountered during a first survey: Galba truncatula, Radix balthica, Anisus leucostoma, Gyraulus albus and Planorbis planorbis. Especially Anisus leucostoma is indicative for a biotope which is occasionally drying out. Two additional terrestrial gastropods could be registered for the graveyard: Arion sylvaticus and Candidula intersecta. The latter has to be considered an invasive species on Terschelling. The presence of two rare species Cecilioides acicula and Limacus flavus was confirmed by additional finds.