This dissertation shows how DNA sequence data derived from museum specimens of the family Vitrinidae were used to unravel some taxonomical conundrums in a hitherto neglected group within the malacological community (Chapters 1 and 2). In addition, phylogenetic problems in Swiss freshwater bivalves (Chapter 3) and introduces new and inexpensive laboratory protocols in conjunction with bioinformatic techniques for recent and ancient mollusc DNA investigations (Chapter 4).