Observations on variation in the mantle of the land snail Monacha cantiana (Montagu) (Pulmonata: Helicidae)

Two distinct forms of mantle pigmentation occur in the European land snail Monacha cantiana (Montagu). These are figured and data are given showing the percentages of the two types of mantle from six populations in different habitats and localities in southern England. Snails with the darker speckled type of mantle were most common on nettles and in dark situations, whilst populations dominated by snails with the pale mantle form were found on grassland in open situations on downs and by the sea. The results confirm and extend earlier observations by Cain (1971) on mantle variation in the same species.