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


L. Watson and M. J. Dallwitz


Morphology. Slug-like, but with a small, posterior external shell covering the mantle.

60–100 mm long when fully extended. Contracting protectively when molested, but not assuming the hemispherical or sub-globular form characteristic of Arionidae. The body creamy white or yellow, or brown, sometimes speckled above with black or brown. The mantle posterior, and covered by the small external shell. The animal with two pairs of tentacles (the anterior pair short). Eyes at the tips of the posterior tentacles.

General biology, ecology. Terrestrial. Principally carnivorous. Lifestyle subterranean (living in burrows several cm deep, and emerging at night to feed mainly on earthworms, but sometimes on other small animals. The seized earthworm withdraws into its burrow, where it is consumed at leisure by the Testacella which is dragged down with it. Hard to find, but best sought in well-manured, worm-rich ground).


Classification. Gastropoda; Pulmonata.

British representation. Testacella (3, “Shelled slug, Shield slug, Maugé’s slug”).

Muscular animals, broad behind and tapering to the small head, which bears two pairs of short, slender tentacles that are not swollen at their tips; with a very large radula, no jaw, and the anus at the hind end.

Illustrations. • Testacella haiotidea, T maugei, T. scutulum (Taylor). • Testacella haliotidea and shells of T. haliotidea, T. scutulum and T. maugei (Ellis). • Testacella haliotidea, T. scutulum, T. maugei (Adams). • Testacella haliotidea, Testacella maugei (Reeve).

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.’.