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 absent (C. acicula being subterranean and blind).

The shell inoperculate; rising-spiral; 5.5 whorled; typically dextral; higher than wide; 4.5–5.5 mm high; 1.2 mm wide; height about 3.19 x the width; high-spired and tapered gradually from the body whorl. The height of the spire about 0.45 x that of the shell. The spire obtuse. The shell tear-shaped; shallowly sutured. The body whorl only slightly convex to moderately convex. The whorls of the spire feebly convex. The whorls neither shouldered nor keeled. The aperture with neither teeth nor calluses. The columella folded to twisted. The shell without an umbilicus. The shell thin-lipped (the mouth edge simple and delicate); thin and translucent (in life, becoming opaque after the death of the animal); pale or white, and very glossy; plain. Morphological comments. The body of the animal colourless.

General biology, ecology. Terrestrial. Lifestyle subterranean (in unwooded calcareous habitats, sometimes occurring at depths of 2 metres or more, often in rock crevices, rootlet holes, or in the cavities within old bones).


Classification. Gastropoda; Pulmonata.

British representation. Cecilioides (1, “Blind snail, Agate snail”).

Illustrations. • Cecilioides acicula (Reeve). • Cecilioides acicula, with Clausiliidae, Chondrinidae, Cochlicopidae, Enidae and Pupillidae (Ellis). • Ceciliodes acicula, with Aciculidae, Clausiliidae, Cochlicopidae, Ellobiidae (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.’.