The families of British non-marine molluscs (slugs, snails and mussels)


L. Watson and M. J. Dallwitz


Morphology. Snails, with a conspicuous, spiral, univalve shell.

The animal with two pairs of tentacles (with a short anterior pair, by contrast with the Vertiginidae). Eyes at the tips of the posterior tentacles.

The shell inoperculate; rising-spiral; 6–7 whorled; typically dextral; 3–4.4 mm in its maximum dimension; higher than wide; 3–4.4 mm high; 1.7–1.9 mm wide; height about 1.74–2.1 x the width. The height of the spire about 0.48–0.62 x that of the shell. The spire obtuse. The shell ovoid-symmetric; rather shallowly sutured to deeply sutured. The body whorl moderately convex. The whorls of the spire feebly convex to moderately convex. The whorls neither shouldered nor keeled. The shell conspicuously and regularly striated across the whorls to not markedly striated across the whorls (with only feeble growth lines). The aperture bearing teeth (sometimes conspicuous, as in Leiostyla, often much reduced, but usually with at least an angular), or bearing calluses, or with neither teeth nor calluses (rarely). The columella folded. The shell with an umbilicus. The shell thick-lipped to thin-lipped (the mouth edge often deflected); thin and translucent to opaque; brown or horn-coloured, glossy or dull; plain.

General biology, ecology. Terrestrial. In diverse locations, moist or dry.

Hermaphrodite; viviparous (Lauria), or oviparous.

Classification. Gastropoda; Pulmonata.

British representation. "Chrysalis snails": Lauria (2), Leiostyla (1), Pupilla (1).

Illustrations. • Lauria cylindracea, Leiostyla anglica and Pupilla muscorum, with Chondrinidae, Clausiliidae, Cochlicopidae, Enidae and Ferussaciidae (Ellis). • Pupilla muscorum (live animal), Lauria cylindracea, Leiostyla anglica (Reeve). • Lauria, Leiostyla and Pupilla, with Chondrinidae, Enidae, Vertiginidae (Adams).

To view the illustrations with detailed captions, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2005 onwards. The families of British non-marine molluscs (slugs, snails and mussels). Version: 4th January 2012.’.