Marshall Ambersnail - Oxyloma decampi
Shell oblong-ovate (succineform), to 15 mm in length and 7.5 mm in width. very thin, surface with minute striae, about 3 whorls with a short spire. Shell coloration is translucent, pale yellow, sometimes with a rose tint. Aperture is ovate, long and relatively thin, about 3/4 the shell length. Sutures are moderately impressed, but not as deep as Catinella. Head and neck covered with minute black dots (Hendricks 2012, Burke 2013). Reports of O. gouldi in Montana are included with this species.
The Succineidae is a most difficult family, with no sure way of distinguishing genera, let alone species, from shell characteristics. In general, Catinella have shorter shells with a rounder aperture and relatively higher spire. Succinea are larger-shelled with more ovate apertures and swelling around the genital opening behind the right tenticle. Oxyloma are similar in size to Succinea but are narrower (larger ratio of height to width), with longer, narrower, ovate apertures (Burke 2013). Specific determination requires the aid of an expert.
Native to eastern North America, west to eastern Montana and Colorado. In Montana, reported east of the Continental Divide from Wibaux County and a questionable report from Madison County. Elevation at the Wibaux County location is 823 m (2700 ft). Range and abundance in Montana are poorly understood; current status needs investigation (Hendricks 2012).
Observations in Montana Natural Heritage Program Database
Number of Observations:
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Priarie riparian areas near rivers, streams,and springs. Canopy species include cottonwoods. Found under woody debris and leaf litter in moist places. Habitat in Montana is poorly described (Hendricks 2012).
No information for Montana.
- 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.
- Additional ReferencesLegend: View Online Publication
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- Harris, S.A. and L. Hubricht. 1982. Distribution of the species of the genus Oxyloma (Mollusca, Succineidae) in southern Canada and adjacent portions of the United States. Canadian Journal of Zoology 60:1607-1611.
- 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. 1948. Land Mollusca of North America (north of Mexico), Volume II Part 2. The Academy of Natural Sciences of Philadelphia Monograph Number 2(2): 521-1113.
- 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"