| | The families of non-marine molluscs of Britain and Ireland (slugs, snails and mussels) |
Morphology. Snails, with a conspicuous, spiral, univalve shell.
The animal with one pair of tentacles only. Eyes at the bases of the tentacles (slightly behind them).
The shell inoperculate; rising-spiral; 4.5–5 whorled (Carychium), or 5–7 whorled (Ovatella and Leucophytia); typically dextral; higher than wide; 1.6–2.5 mm high (Carychium), or 5–8 mm high (Leucophytia, Ovatella); 0.8–0.9 mm wide (Carychium), or 2.5–3.8 mm wide (approximately, in Leucophytia and Ovatella); height about 1.8–2.1 x the width; high-spired and tapered gradually from the body whorl. The height of the spire about 0.3–0.47 x that of the shell. The spire acute to obtuse. The shell tear-shaped (in Ovatella and Leucophytia), or ovoid-symmetric (Carychium); shallowly sutured to deeply sutured (more deeply so in Carychium). The body whorl moderately convex. The whorls of the spire feebly convex to very strongly convex. The whorls neither shouldered nor keeled. The aperture lunate (or auriculate); bearing teeth. The columella folded, or twisted. The shell without an umbilicus. The shell thick-lipped; thin and translucent (Carychium), or opaque (Ovatella and Leucophytia); colourless and semi-transparent when fresh in Carychium, and white, brown or yellowish in Leucophytia and Ovatella; plain.
General biology, ecology. Terrestrial, or terrestrial to freshwater aquatic (Carychium minimum being more or less amphibious, common in moist places under rotting logs or in leaf litter), or semi-marine (Ovatella and Leucophytia, living around high tide mark, but terrestrial rather than aquatic). Breathing air directly via the lung-like mantle cavity.
Hermaphrodite (but individuals acting as either male or female when mating).
Classification. Gastropoda; Pulmonata.
Representation in Britain and Ireland. Carychium (2, “Herald snails, Sedge snail”), Leucophytia (1), Ovatella (1, “Mouse-eared snail”).
Illustrations. • Carychium minimum, Leucophytia bidentata, Ovatella myosotis (Reeve). ELLOBIIDAE. 1, Carychium minimum Müller, "Least Herald Snail". 2, Ovatella myosotis (Draparnaud), "Mouse-eared Snail". 3, Leucophytia bidentata (Montagu). From Reeve (1863, with scales added). • Carychium minimum, with Aciculidae, Clausiliidae, Cochlicopidae, Ferussaciidae (Adams). ELLOBIIDAE. 9, Carychium minimum Müller, "Least Herald Snail, Sedge Snail". CLAUSILIIDAE. 1a and 1b, Clausilia bidentata (Strom), "Common Door Snail, Two-toothed Snail". 2a and 2b, Macrogastra rolphii (Turton), "Rolph’s Door Snail". 3a and 3b, Cochlodina laminata (Montagu), "Plaited Door Snail", with detail of an oral lamina. 4a and 4b, Balea biplicata (Montagu), "Thames Door Snail". 5, Balea perversa (Linn.), "Tree Snail". COCHLICOPIDAE. 6, Cochlicopa lubrica (Müller), "Slippery Moss Snail". 7a and 7b, Azeca goodalli (Férussac), "Three-toothed Moss Snail". FERUSSACIIDAE. 8, Cecilioides acicula (Müller), "Blind Snail, Agate Snail". ACICULIDAE. 11a, Acicula fusca (Montagu), "Point Snail", with (11a) detail of the operculum. TO BE IDENTIFIED. 12, Stenogyra goodallii Miller, name not located in recent lists, and identity not established. From Adams (1890).
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, 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. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2005 onwards. The families of non-marine molluscs of Britain and Ireland (slugs, snails and mussels). Version: 5th August 2019. delta-intkey.com’.
