West Palearctic and tropical Bivalves: Arcoida, Myoida, Mytiloida, Nuculoida, Ostreoida, Pholadomyoida, Pterioida, Solemyoida, Trigonioida, Veneroida. Emphasis on Pectinidae, and Veneridae. Important collection West Palearctic marine Gastropods and marine micro mollusks, as well as a representative collection non-West Palearctic gastropods. Smaller representative collection of European land- en freshwater snails. Taxa include: Caenogastropoda, Cocculiniformia, Heterobranchia, Neritimorpha, Opistobranchia, Patellogastropoda, Pulmonata and Vetigastropoda. The Polyplacophora collection holds the private collection of Frans J.A. Slieker, author of 'Chitons of the World' (2000) and is the second largest in the Netherlands after the collection of the 'Nederlands Centrum voor Biodiversiteit Naturalis (Leiden)'. Emphasis on West-Palearctic species. Taxa include: Leptochitonidae, Hanleyidae, Mopaliidae, Ischnochitonidae, Callochitonidae, Callistochitonidae, Lepidochitonidae, Schizochitonidae, Chitonidae, Cryptoplacidae and Acanthochitonidae. Representative collection West-Palearctic Scaphopoda. Small, but representative collection of non-West-Palearctic species. Taxa include: Gadilinidae, Dentaliidae, Fustiariidae, Laevidentaliidae, Entalinidae, Pulsellidae and Gadalidae. Important collections of Eocene (Paris Basin), Miocene (Winterswijk, Miste, Dingden) and Pliocene/Pleistocene mollusks (Westerschelde, de Kaloot, Antwerp Harbour). Taxa include: Arcoida, Caenogastropoda, Cocculiniformia, Dentaliida, Gadilida, Heterobranchia, Myoida, Mytiloida, Neritimorpha, Nuculoida, Opistobranchia, Ostreoida, Patellogastropoda, Pholadomyoida, Pterioida, Pulmonata, Sepiida, Veneroida and Vetigastropoda.