E-Fauna BC Home

Allogona ptychophora A.D. Brown, 1870)
Idaho Forestsnail
Family: Polygyridae
Species account author: Robert Forsyth.
Introduction to the Land Snails of BC

Photograph

© Robert Forsyth     (Photo ID #303)

Map

E-Fauna BC Static Map

Distribution of Allogona ptychophora in British Columbia in British Columbia

Species Information

Diagnosis

The shell is most similar to that of Allogona townsendiana but smaller, with fewer malleations and more regular colabral riblets. In some, a weak callus or low, poorly developed denticle is occasionally present on the parietal.

Shell

Large, heliciform, light brown or yellow-brown, with lighter coloured irregular but ribs; periostracum never hairy; lip thickened and expanded, white; aperture without denticles, except very occasionally with a low parietal denticle or callus.

Biology


Carney (1966) noted that in Montana, and as seen along the Elk River in B.C. (Forsyth 2004), most snails position their shells with the apex directed downward during the winter hibernation. Carney found that mortality was greater when the shell was not positioned in this fashion and speculated that this orientation of the shell might be important for over-wintering survival.

Habitat


Interior Cedar-Hemlock forests; mesic wooded areas generally.

Distribution


Global Distribution

Western North America, from BC and Montana, west of the Continental Divide, south through Idaho, to Washington east of the Columbia River, and northeast Oregon (Pilsbry 1940). This species occurs east of the range of Allogona townsendiana, except for down the lower part of the Columbia River, where both have been found together (Pilsbry 1940).

BC Distribution

Throughout the southern Kootenay, Columbia, and Elk river drainages; north as far as the vicinity of Revelstoke, Salmon Arm, and Salmon Arm and Shuswap Lake (Forsyth 2004; map data). Not on the coast and Vancouver Island [map data incorrect].

Ecozone

Montane Cordillera.

Notes


Etymology

Genus derived from the Greek "allos" meaning "other" or "different" + "gona", "genitalia"; the gender is feminine. Species epithet from the Greek, "ptychos", “fold” + "phoro", "to bear" or “carry”.

Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)		COSEWIC
NativeS4YellowNot Listed



BC Ministry of Environment: BC Species and Ecosystems Explorer--the authoritative source for conservation information in British Columbia.

Additional Range and Status Information Links

NatureServe Explorer

General References

Google Scholar Search

© 2014 E-Fauna BC  Contact us