Non-marine molluscs have been analysed from samples of two tufa deposits in Suffolk. The first was collected in the 1930s from a site near Tuddenham in the Finn Valley and the second was obtained in 1980 from a temporary section at Chantry near Ipswich. Comparisons with more complete radiocarbon-dated sequences from south-east England indicate that the former accumulated sometime between ~9500–8500 BP and the latter between ~8500–8000 BP. Both faunas comprise communities which cannot be matched at any site in Britain today. The occurrence of Discus ruderatus and Nesovitrea petronella, two taxa now extinct in Britain, is of particular interest.