Oreohelix strigosa

Oreohelix strigosa (Gould, 1846)
Rocky Mountainsnail

  • Oreohelix strigosa Gould 1846 in 1846–1850: 166.
  • Oreohelix strigosa canadica Berry 1922: 6, pl. 1, figs 6, 7.
  • ? Other forms and subspecies; see Pilsbry (1939) and Burke (2013).
Oreohellix strigosa; near Donald, BC (RGF 09.113.2664).

Identification. Shell depressed. Spire rather low, domed. Whorls ca 6, convex (in adults). Last whorl descending in adults. Suture rather shallow. Periphery rounded or weakly angular (adults), medial on whorl. Aperture subovate, edentulous. Lip simple, thin or slightly thickened. Umbilicus ca ¼ of shell width. Teleoconch with irregular wrinkle-like incremental striae; some faint spiral striae evident. Shell dull, pale grey to pale brown, usually with 1 or 2 brown spiral bands. Width to 16–26 mm (wider than high).

Animal buff.

Habitat. Forests. In leaf litter, under dead wood, vegetation, and rocks and in scree slopes.

Global range. In the broad sense, south-eastern BC, eastern portions of Washington and Oregon, south to Arizona and New Mexico (Pilsbry 1939), but not Cypress Hills, which is O. cooperi.

Canadian range. South-eastern BC: Rocky Mountain Trench north from the US border to the vicinity of Donald (the northernmost occurrence of Oreohelix anywhere).

Etymology. Latin: strigosus, full of streaks.

Remarks. Numerous putative subspecies and infrasubspecific taxa have been named for populations throughout the species’ range (see Pilsbry 1939); these have not been included in the above synonymy, as their status (synonym, valid subspecies, or separate species) has not been established. Oreohelix strigosa cooperi is now known to be a separate species. Berry (1922) described Oreohelix strigosa canadica from Donald, British Columbia, which Pilsbry (1939) considered to be a synonym of the typical O. strigosa. DNA barcoding of specimens from Donald and further south in BC suggest that the Donald population is the same species (A. Nicolai unpubl. data).

  • Berry SS (1922) Land snails from the Canadian Rockies. Victoria Memorial Museum, Bulletin 36: 1–19.
  • Burke TE (2013) Land snails and slugs of the Pacific Northwest. Oregon State University Press, Corvallis, Oregon, 344 pp.
  • Gould AA (1846–1850) [Shells collected by the United States Exploring Expedition under the command of Charles Wilkes.] Proceedings of the Boston Society of Natural History 2: 141–145, 148–152 [July 1846]; 153–156, 159–162, 165–167 [August 1846]; 170–173, 175–176 [September 1846]; 177–179, 180–184, 185–187, 190–192 [“November 1846”; probably between 16 December 1846 and March 1847]; 196–198, 200–203, 204–208 [March 1847]; 209, 210–212, 214–215, 222–224 [June 1847]; 225, 237–239 [July 1847]; 251–252 [December 1847] • 3: 73–75 [November 1848]; 83–85, 89–92 [March 1849]; 106–109 [April 1849]; 118–121, 140–144 [May 1849]; 151–156, 169–172 [January 1850]; 214–219 [May 1850]; 252–256 [June 1850], 276–278 [July 1850]; 292–296, 309–312 [November 1850]; 343–348 [December 1850].
  • Pilsbry HA (1939) Land Mollusca of North America (north of Mexico). Vol. I, Part 1. The Academy of Natural Sciences of Philadelphia, Monographs3: i–xvii + 1–573 + i–ix.