Hygromiidae

Hygromiidae is a family of land snails within the class Gastropoda and the superfamily Helicoidea. They are terrestrial pulmonate gastropods that include a large number of genera, with Hygromia and Trochulus among the better known examples. Members of this family are commonly referred to as hygromiid snails or hairy snails, reflecting the characteristic periostracal hairs found on many species.

Shells in Hygromiidae are generally small to medium in size and show a range of shapes from globular to depressed helicoid. A distinctive feature in many species is a periostracum bearing hairs or bristles, which can give the shell a hairy appearance; these hairs may wear away on older individuals. Shells are typically thin and may have varying coloration and banding. The aperture and umbilicus can vary, contributing to the diversity of forms within the family.

Geographically, Hygromiidae is most diverse in Europe, parts of North Africa, and western Asia, with additional representatives on several Mediterranean islands and other regions. They inhabit a variety of terrestrial habitats, including woodlands, grasslands, shrublands, and gardens, often in moist microhabitats. Activity is commonly nocturnal or after rain, and many species aestivate during dry periods.

Ecology and life history are typical of many terrestrial pulmonates: most species are herbivorous, feeding on plant material, detritus, and microflora. They are usually hermaphroditic and reproduce by mating with another individual, laying eggs in soil or leaf litter. Conservation status varies by species, with some facing threats from habitat loss and introduced predators. The taxonomy and phylogenetic relationships within Hygromiidae have undergone revisions as new data become available.