Amber Glass - Nesovitrea electrina
Retinella electrina, Polita hammonis, Nesovitrea hammonis, Vitrea hammonis, Vitrea radiatula, Helix electrina, Hyalina pellucida
A small shell, to about 5 mm diameter and 2.5 mm in height, flattened heliciform with a low spire, surface with narrow widely-spaced axial grooves but no fine spiral striae, about 3 1/2 to 4 whorls, the last rapidly increasing in width. Shell coloration is translucent to transparent pale amber to brownish. Aperture is oblique crescent-shaped, wider than tall and without teeth (denticles), lip not thickened, periphery rounded; umbilicus is relatively narrow, about 1/6 the shell diameter. Animal is dark to blackish on the head and tentacles. All generic forms previously referred to as “hammonis” are treated here as Nesovitrea electrina, although the name may have been applied by some authors to N. binneyana (Hendricks 2012, Burke 2013). Internal anatomy is described by Pilsbry (1946).
A combination of small size (< 5.5 mm diameter), narrow umbilicus, small number of whorls (3.5 to 4.0), whorls increasing in size with the last obviously enlarged, transparent and shiny shell lacking spiral striations or riblets, distinguish Nesovitrea from other genera. N. electrina differs from N. binneyana by having a shell diameter > 4.0 mm, shell a pale amber to brownish color, and the live animal blackish on head and tentacles.
Alaska to Labrador, in the west to Arizona and New Mexico. In Montana, reported on both sides of the Continental Divide, from nine counties: Flathead, Gallatin, Lake, Lincoln, Park, Ravalli, Sanders, Wheatland, Wibaux. Elevation range is 823 to 1975 m (2700 to 6480 ft), unverified report in Ravalli County to 2743 m (9000 ft) or higher. Appears to be uncommon in most locations; six were observed at one locality in Park County in late August (Hendricks 2012).
Observations in Montana Natural Heritage Program Database
Number of Observations:
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(Observations spanning multiple months or years are excluded from time charts)
A variety of wooded locations, often more restricted to moister sites, such as riparian zones, than Nesovitrea binneyana. Canopy species include Engelmann spruce, Douglas-fir, western larch, aspen, cottonwood, and Rocky Mountain juniper; secondary canopy includes paper birch, alder, and willow. Found under woody debris, rocks, bryophyte mats, in leaf litter or duff (Hendricks 2012).
- Literature Cited AboveLegend: View Online Publication
- Burke, T. E. 2013. Land snails and slugs of the Pacific Northwest. Corvallis, OR: Oregon State University Press. 344 p.
- Hendricks, P. 2012. A Guide to the Land Snails and Slugs of Montana. A report to the U.S. Forest Service - Region 1. Montana Natural Heritage Program, Helena, MT. vii + 187 pp. plus appendices.
- Pilsbry, H.A. 1946. Land Mollusca of North America (north of Mexico), Volume II Part 1. Academy of Natural Sciences of Philadelphia Monograph Number 3 (2):1-520.
- Additional ReferencesLegend: View Online Publication
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- Beetle, D. E. 1961. Mollusca of the Big Horn Mountains. The Nautilus 74:95-102.
- Beetle, D.E. 1989. Checklist of recent Mollusca of Wyoming, U.S.A. The Great Basin Naturalist 49(4):637-645.
- Berry, S.S. 1913. A list of Mollusca from the Mussellshell Valley, Montana. Nautilus 26:130-131.
- Berry, S.S. 1916. Notes of Mollusca of central Montana. Nautilus 29:124-128.
- Brunson, R.B., and U. Osher. 1957. Haplotrema from western Montana. Nautilus 70: 121-123.
- Forsyth, R.G. 2004. Land snails of British Columbia. Royal British Columbia Museum: Victoria, British Columbia, Canada. 188 pp.
- Frest, T.J. and E.J. Johannes. 2001. An annotated checklist of Idaho land and freshwater mollusks. Journal of the Idaho Academy of Science 36(2):1-51.
- Squyer, H. 1894. List of shells from the vicinity of Mingusville, Montana. The Nautilus 8:63-65.
- Vanatta, E.G. 1914. Montana shells. Proceedings of the Academy of Natural Sciences of Philadelphia 66:367-371.
- Additional Sources of Information Related to "Snails / Slugs"