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. Eyes at the tips of the posterior tentacles.

The shell inoperculate; rising-spiral; 5–6.5 whorled; typically dextral; 13–23 mm in its maximum dimension; wider than high; 10–16 mm high; 13–23 mm wide; height about 0.75 x the width; with the body whorl predominating and the spire small and short. The height of the spire about 0.15 x that of the shell. The shell deeply sutured. The body whorl very strongly convex. The whorls of the spire moderately convex. The whorls neither shouldered nor keeled. The shell not markedly striated across the whorls (the growth ridges rather coarse and irregular, and crossed by much finer spiral striations). The aperture round to oval; with neither teeth nor calluses. The shell with an umbilicus. The umbilicus of medium width. The shell thick-lipped (the lip everted basally, and with a white internal rib); opaque; white to pale greenish yellow; plain (though “sometimes with a faint darker band at the periphery”). Morphological comments. The animals sulphur-yellow to yellowish grey.

General biology, ecology. Terrestrial. Found in Kent in the shade, in lush, damp vegetation on roadside banks.

Hermaphrodite. The stalk of the bursa copulatrix without a diverticulum. Courtship involving exchanges of ‘love darts’ prior to mating (the reproductive structures including more than one dart sac); the darts calcareous.

Classification. Gastropoda; Pulmonata.

British representation. Bradybaena (1, “Bush snail”).

This family is probably indistinguishable from Helicidae on shell characters alone.

Illustrations. • Bradybaena fruticum (Ellis).

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.’.