MolluscIreland - land and freshwater
  • Merdigera obscura (O. F. Müller 1774) Lesser bulin
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Merdigera obscura
© Dr Roy Anderson
Merdigera obscura
© Dr Roy Anderson
Merdigera obscura
© Dr Roy Anderson

Map hosted by the National Biodiversity Data Centre, Waterford
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A brown, conical shell of characteristic, slightly barrelled shape and oval aperture framed by a broad, reflected rim. Found, often covered by algal deposits, on rocks and walls, but very local in Ireland.

Key characteristics

  • A brown, conical shell of characteristic, slightly barrelled shape
  • Surface mid to dark brown with fine, irregular radial growth lines
  • Whorls convex and sutures moderately deep
  • Umbilicus closed

Size

8.5-9 mm.

World Distribution

Widespread in western and central Europe to southern Scandinavia and the British Isles. Distribution type: European Southern-temperate (83).

Irish Distribution

Widely distributed in Ireland but absent from most of the north, west and south-west and nowhere common. Less rare in the eastern central plain.

Ecology

  • Thermophilic, preferring warm, south-facing places
  • Principally on minimally disturbed calcareous rocks and walls
  • Often in light woodland or scrub

Red List status

  • Endangered (EN).

Wikipedia link

Wikipedia page for Merdigera obscura

 Anderson, R., (2016). Merdigera obscura (O. F. Müller 1774). [In] MolluscIreland.
http://www.habitas.org.uk/molluscireland/species.asp?ID=117 Accessed on 2017-10-22.