Minute Gem - Hawaiia minuscula
Zonitoides miniscula, Pseudohyalina miniscula
A very small shell, to 2.5 mm diameter and 1.2 mm in height, flattened heliciform, nearly smooth with uneven striations on the upper surface, about 4 to 4 1/2 whorls, the last tubular and not greatly expanded. Shell coloration is pale gray to flesh-colored. Aperture is crescent-shaped, rounded at the periphery; umbilicus wide, about 1/3 the shell diameter. The animal is light-colored (Hendricks 2012, Burke 2013). Internal anatomy is described by Pilsbry (1946).
Differs from other very small heliciform shells by a combination of shell possessing a smooth surface (including the embryonic whorls), 4-5 whorls with body whorl not enlarged, lip not flared or reflected, wide umbilicus, shell pale grayish or flesh-colored.
Widespread in North America although probably introduced in many areas; probably introduced throughout the Caribbean and Japan. In Montana, reported from five counties on both sides of the Continental Divide: Broadwater, Flathead, Musselshell, Wheatland, Wibaux. Elevation range is 823 to 1373 m (2700 to 4505 ft). At least two Montana records are shells from drift material along water courses, and whose origins may be distant from the reported locations (Hendricks 2012).
Observations in Montana Natural Heritage Program Database
Number of Observations:
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Frequents a variety of sites, wooded to relatively exposed and arid. Found under limestone and sandstone rocks in sites sparsely vegetated with juniper and grass, in willow litter, also under Douglas-fir and ponderosa pine canopy (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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- 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.
- 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.
- Henderson, J. 1936. Mollusca of Colorado, Utah, Montana, Idaho, and Wyoming, supplement. University of Colorado Studies 23(2): 81-145.
- Squyer, H. 1894. List of shells from the vicinity of Mingusville, Montana. The Nautilus 8:63-65.
- Additional Sources of Information Related to "Snails / Slugs"