Land Mollusca are common fossils in Quaternary sediments and their analysis for environmental study is now standard practice. Literature for identifying fossil shells is scanty and generally relies on characters present only in adults. Since most fossil samples are composed largely of fragmentary or juvenile shells other characters must be used. Differences in shell microsculpture are often diagnostic. A selection of scanning electron photomicrographs illustrating many of the commoner species present in British Postglacial deposits is presented in order to facilitate specific determination of fossil material.