|
| 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 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).
Hermaphrodite.
Classification. Gastropoda; Pulmonata.
Representation in Britain and Ireland. Cecilioides (1, “Blind snail, Agate snail”).
Illustrations. • Cecilioides acicula (Reeve). FERUSSACIIDAE. Cecilioides acicula (Müller), "Blind Snail", "Agate Snail". From Reeve (1863, with approximate scale added). • Cecilioides acicula, with Clausiliidae, Chondrinidae, Cochlicopidae, Enidae and Pupillidae (Ellis). FERUSSACIIDAE. 8, Cecilioides acicula (Müller), "Blind Snail, Agate Snail". 4.5–5.5 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. CHONDRINIDAE. 8–9, Abida secale (Draparnaud), "Large Chrysalis Snail", 6.0–8.5 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. 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. 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. • Ceciliodes acicula, with Aciculidae, Clausiliidae, Cochlicopidae, Ellobiidae (Adams). FERUSSACIIDAE. 8, Cecilioides acicula (Müller), "Blind Snail, Agate 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". ELLOBIIDAE. 9, Carychium minimum Müller, "Least Herald Snail, Sedge 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’.
