A lithological description of sediments of Holocene and Pleistocene age (Duinkerke III Deposits, Holland Peat and Twente Formation) is given and a small mollusc fauna from the Duinkerke III Deposits is evaluated. The common occurrence of the gastropod Odostomia (O.) aff. plicata (Montagu, 1803) is surprising. It is the first time that this species is reported from the Dutch Holocene deposits.