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Helicid Snails
II: Helicinae
 Helicid Snails III: Mediterranean Helicidae |
Abbreviations used: W: Width (of shell); H: Height; N: Number of whorls.
Explanation of
shell characters as means of identification.
Helicid snails (Helicidae) are the the Roman Snail's (Helix pomatia) nearest relatives. This family's members usually have got a spherical shell, that may be flattened. Only in few cases the shell has got apertural teeth. Helicid snails produce a love dart, that is put into action during the (usually mutual) courtship, before copulation (See: Reproduction of Helix pomatia).
The natural area of distribution today spreads over the whole western Palearctic (see: Faunal provinces), but it is assumed, that the Helicidae snail family originated from Southern Europe and the Mediterranean.
The Helicidae family is divided into several subfamilies: The Ariantinae subfamily with the copse snail (Arianta arbustorum) and its relatives. Another subfamily is the Helicinae, containing Helix pomatia, the Roman snail, and its relatives. Additionally to Helix itself there are several other edible snail species in the Helicinae, some of which, too, are of economical importance (see: Snail cultivation).
Roman snail (Helix pomatia)
Brown garden snail (Cornu aspersum)
In contrary to other Helicidae snails the juveniles of the Ariantinae subfamily may have hairy shells. The love dart does not possess a crown and has got a two-edge, lancet-shaped blade (see also: Koene, J.M. 2005).
Copse snail - Arianta arbustorum (Linnaeus 1758).
 Copse snail (Arianta arbustorum). [RN] |
 Picture: Helmut Nisters. |
Description: The copse snail has got a spherical shell with a conical spire. The shell usually is chestnut brown in colour with straw yellow spots and a dark band. The umbilicus is usually completely concealed by the columellar part of the distinct white apertural lip.
Arianta arbustorum is one of the most variable snail species: There are numerous geographical races, valley and mountain forms. Similarly to the banded snails, selection by snail eating thrushes may also cause an additional variety in copse snail shells depending on ground type and vegetation cover.
During copulation a special stimulation organ is extended from the genital atrium.
Size: W: 14 - 28 mm; H: 10 - 22 mm; N: 5 - 6.
Habitat and Distribution: In spite of its name the copse snail occurs in open country as well as in forests (copses), preferring humid habitats. In the mountains it will climb until 2700 m above sea level.
The species is distributed over Northwest and Central Europe, including the Alps and the Carpathians. From the Spanish Eastern Pyrenees it occurs until Norway and Iceland. In Ireland it only occurs in the North, in the Eastern Baltic Sea Region only near the coast. In a dispersed pattern the copse snail can be found in the East as far as the Western Ukraine.
Lapidary Snail - Helicigona lapicida (Linnaeus 1758)
 Lapidary snail (Helicigona lapicida). [RN] |
Description: The lapidary snail has got a characteristically lens-shaped shell with a clearly visible keel. The shell has a grey-brown colour with blurred red-brown spots. Because of the shell form the aperture is very oblique, the lip is distinct and whitish. It is set off the shell surface. The umbilicus is wide and open.
The characteristic form of its shell enables the lapidary snail to withdraw into crevices in rock or bark during dryness.
Size: W: 12 - 20 mm; H: 7 - 9mm; N: 5 ½.
Habitat and Distribution: Shady rocks and walls (especially those overgrown with ivy) and tree trunks, especially beech, hornbeam and sycamore. Lapidary snails are to be found mainly in hill country and mountainous forests in Western and Central Europe.
They occur from Central Portugal to Central Scandinavia, in Britain up to Southern Scotland. In Southern Ireland the species only occurs as a relict from the warm postglacial. In the Alps the species only occurs north of the main ridge, in the East it is spread as far as the Polish Jura and the Western Carpathians.
Some Ariantinae:
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| Helicigona lapicida (16 mm) - Lapidary Snail | Chilostoma cingulatum baldense (25 mm) - Rock Snail | Isognomostoma isognomostomos (9 mm) - Mask Snail |
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Source: Helmut Nisters: The Rockers and Wallers. |
Part 2: Subfamily Helicinae.
Part 3: Mediterranean Helicidae.