Growth of Chilostoma faustinum (Rossmässler, 1835) was recorded under natural conditions in Romincka Forest (NE. Poland), one of the northernmost localities of the species. During the growing season (April–October) the average growth rate was 0.22 whorl/month. In the local conditions Ch. faustinum Leeds three growing seasons to complete its shell growth. Shells of Ch. faustinum from Romincka Forest are slightly smaller than in the other studied populations: their average width is 16.5 mm (range 13–19 mm); and the average number of whorls is 4.5 (range 4–5).
Chemical composition of shells of Cepaea vindobonensis (Férussac) from sites with carbonate and carbonate-silica bedrock in central and south-eastern Poland and from alluvial deposits of the Vistula River indicates a relation between the chemism of the environment in which the species occurs and the chemical composition of the shells. The ability to accumulate heavy metals in the shell of C. vindobonensis makes this species a potential bioindicator.