Vitrea contracta

Vitrea contracta (Westerlund, 1871)
Contracted Glass-Snail

  • Zonites (Vitrea) crystallina var. contracta Westerlund 1871: 56.
Vitrea contracta; Queen Elizabeth Park Vancouver, BC (RGF 11.015.3966); width 2.15 mm.

Identification. Shell subdiscoidal. Spire very low, conic. Whorls ca 4–4½, slowly enlarging, tightly coiled. Periphery rounded, above middle. Suture moderately indented. Protoconch smooth. Teleoconch smoothish, with weak incremental lines. Aperture, narrowly lunate, edentulous. No barriers inside whorls. Lip thin, simple. Umbilicus narrow, deep, ca 1/7 of shell width. Shell transparent or translucent, colourless or milky white, glassy. Shell width to 2.6 mm.

Animal pale tan to ivory white; ocular tentacles translucent, with black eye spots (Roth 1977).

Habitat. Gardens and waste ground. Under ivy and other vegetation, in leaf litter, and under rocks and dead wood.

Canadian range. Introduced. British Columbia: east coast of Vancouver Island north to Nanaimo, the Gulf Islands; Greater Vancouver and the Fraser Valley east to near Chilliwack; Kamloops; Skidegate, Haida Gwaii. Ontario: Toronto (Forsyth 2004, unpubl.).

Etymology. Latin, contractus, “narrowed”, likely in reference to the aperture.

References

  • Forsyth RG (2004) Land snails of British Columbia. Royal BC Museum Handbook. Royal British Columbia Museum, Victoria, iv + 188 + [8] pp.
  • Roth B (1977) Vitrea contracta (Westerlund) (Mollusca: Pulmonata) in the San Francisco Bay area. The Veliger 19: 429–430.
  • Westerlund CA (1871) Fauna Molluscorum Terrestrium et Fluviatilium Sveciæ, Norvegiæ et Daniæ. Sveriges, Norges och Danmarks land och sötvatten-mollusker. I. Landmolluskerna. Adolf Bonnier, Stockhom, [5] + 296 pp.