Helix pomatia

Helix pomatia Linnaeus, 1758
Roman Snail

  • Helix pomatia Linnaeus 1758: 771.
  • Many additional synonyms in Europe.
Helix pomatia; Canatara Park, Sarnia, Ontario (James Kamstra photo).

Identification. Shell subglobose. Spire elevated, conical. Whorls ca 4, convex. Periphery rounded, medial on the last whorl. Protoconch smooth. Teleoconch with irregular, low colabral ridges/riblets and spiral rows of weak granules. Aperture large, subovate-rounded, inside showing external shell colour, without teeth. Last whorl descending when shell full-grown. Lip not scarcely thickened in adults, narrowly flared outward, more strongly expanded near the columella. Umbilicus closed or a narrow cleft. Shell opaque, pale grey-brown, with lighter and darker colabral streaks and, in general, 2–5 spiral bands (sometimes rather weakly marked or absent); columellar lip pinkish. Width to 42 mm (higher than wide).

Habitat. In parks and gardens.

Canadian range. Introduced. Southern British Columbia: Melrose and Revelstoke. Southern Ontario: Sarnia. Populations are apparently reproducing (Forsyth & Kamstra 2019).

Etymology. Greek, poma, “a lid” (Kennard & Woodward 1926), perhaps in reference to the calcified epiphragm used to close the aperture during times of aestivation or hibernation.

  • Forsyth RG, Kamstra J (2019) Roman Snail, Helix pomatia (Mollusca: Helicidae), in Canada. The Canadian Field-Naturalist 133: 156–159.
  • Kennard AS, Woodward BB (1926) Synonymy of the British non-marine Mollusca (Recent and post-Tertiary). British Museum (Natural History), London, xxiv + 447 pp.
  • Linnaeus C (1758) Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata. Laurentii Salvii, Holmiæ, [4] + 824 pp.