| | 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 two pairs of tentacles. Eyes at the tips of the posterior tentacles.
The shell inoperculate; rising-spiral; 6.5–8 whorled; typically dextral; 8.5–9 mm in its maximum dimension; higher than wide; 8.5–9 mm high (E. obscura), or 14–17 mm high (E. montana); 3.7 mm wide (E. oscura), or 6.7 mm wide (E. montana); height about 2.32–2.33 x the width; high-spired and tapered gradually from the body whorl. The height of the spire about 0.49–0.52 x that of the shell. The spire acute to obtuse. The shell tear-shaped; fairly shallowly sutured. The body whorl moderately convex. The whorls of the spire feebly convex to moderately convex. The whorls neither shouldered nor keeled. The shell not markedly striated across the whorls (sculptured only with fine growth lines and/or striae). The aperture with neither teeth nor calluses. The columella folded. The shell with an umbilicus. The umbilicus small (and deep). The shell thick-lipped; thin and translucent to opaque; light brown or transparent horn-coloured, not very glossy; plain.
General biology, ecology. Terrestrial. In ground litter in woods, hedgerows, etc., mainly on base-rich soils, often climbing up tree trunks or walls in wet weather.
Hermaphrodite. Courtship not involving ‘love darts’.
Classification. Gastropoda; Pulmonata.
Representation in Britain and Ireland. Ena (2, “Bulin snails”).
Illustrations. • Ena montana and Ena obscura, with Clausiliidae, Chondrinidae, Cochlicopidae, Ferussaciidae and Pupillidae (Ellis). ENIDAE. 16, Ena montana (Draparnaud), "Mountain Bulin", 14–17 mm.; 17–18, Ena obscura (Müller), "Lesser Bulin", 8.5–9.0 mm. COCHLICOPIDAE. 22–23, Cochlicopa lubrica (Müller), "Slippery Moss Snail", 5–7 mm. 26–27, Azeca goodalli (Férussac), "Three-toothed Moss Snail", 5.5–7.0 mm. CLAUSILIIDAE. 10, Macrogastra rolphii (Turton), "Rolph's Door Snail", 11–14 mm. 11, Clausilia bidentata (Ström), "Common Door Snail", or "Two-toothed Door Snail". 12, Clausilia dubia Draparnaud, "Craven Door Snail, 11–14(-16) mm. 13, Balea biplicata (Montagu), "Thames Door Snail", 16–18 mm. 14, Cochlodina laminata (Montagu), "Plaited Door Snail", 15–17 mm. 15, Balea perversa (L.), "Tree Snail", 8–10 mm. CHONDRINIDAE. 8–9, Abida secale (Draparnaud), "Large Chrysalis Snail", 6.0–8.5 mm. PUPILLIDAE. 3–4, Pupilla muscorum (L.), "Moss Chrysalis Snail", 3–4 mm. 5–6, Lauria cylindracea (da Costa), "Common Chrysalis Snail", 3.0–4.4 mm. 7, Leiostyla anglica (Wood), "English Chrysalis Snail", 3.0–3.7 mm. FERUSSACIIDAE. 28, Cecilioides acicula (Müller), "Blind Snail" or "Agate Snail", 4.5–5.5 mm. From Ellis (1926); all displayed at the same enlargement, to assist comparisons. • Ena montana and E. obscura, with Chondrinidae, Pupillidae, Vertiginidae (Adams). ENIDAE. 8, Ena montana (Draparnaud), "Mountain Bulin"; 9, Ena obscura (Müller), "Lesser Bulin". CHONDRINIDAE. 10, Abida secale (Draparnaud), "Large Chrysalis Snail". PUPILLIDAE. 11, Leiostyla anglica (Wood), "English Chrysalis Snail"; 12, Lauria cylindracea (Da Costa), "Common Chrysalis Snail"; 13, Pupilla muscorum (Linn.), "Moss Chrysalis Snail". VERTIGINIDAE. 14, Vertigo antivertigo (Draparnaud), "Marsh Whorl Snail"; 15, Vertigo moulinsiana (Dupuy), "Des Moulins’ Whorl Snail"; 16, Vertigo pygmaea (Draparnaud), "Common Whorl Snail"; 17, Vertigo alpestris Alder, " Mountain Whorl Snail"; 18, Vertigo substriata (Jeffreys), "Striated Whorl Snail"; 19, Vertigo pusilla (Müller), "Wall Whorl Snail, Wry-necked Whorl Snail"; Vertigo angustior Jeffreys, " Narrow-mouthed Whorl Snail". 21, Columella edulenta agg., i.e. C. edulenta (Draparnaud) or C. aspersa Waldén, "Toothless Chrysalis Snail". 22, cf. Truncatellina sp. (labelled by Adams Vertigo minutissima Hartmann, a name not yet located elsewhere. His illustration, morphological description, and the distribution he gave suggest an amalgam of Truncatellina cylindrica and T.callicratis, only recently distinguished from one another at specific level.). 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’.
