Montana Field Guide

A moderately small shell, up to about 6 mm diameter and 4 mm in height, heliciform with a low and small spire, very fragile, 2 1/2 to 3 whorls, the last rapidly enlarging to form about half of the shell. Shell coloration is pale greenish or yellowish to almost colorless, translucent to transparent, shell smooth and glossy, with low axial wrinkles. Aperture is large and thin, oblique-ovate and rounded, without teeth; umbilicus tiny. Animal brownish, head and tentacles darker grayish (Hendricks 2012, Burke 2013). Internal anatomy is described by Forsyth (2004).

No other land snail in the Pacific Northwest resembles this species in combination of small size, color (pale yellowish to nearly colorless), smooth and glossy shell, and a small number of whorls with the last rapidly expanding to the aperture. Live animals may appear to have a brownish shell, but that is the body color of the animal visible through the shell.

Forest with broadleaf or mixed broadleaf-conifer canopy, near moisture; in campgrounds and roadside ditches, isolated aspen stands. Canopy species include cottonwoods, aspen, Douglas-fir, Engelmann spruce, lodgepole pine, ponderosa pine, whitebark pine, subalpine fir and western redcedar, secondary canopy includes alder, paper birch, hawthorn, snowberry, thimbleberry, willow and mountain maple. Often found in more open areas under woody debris and bark, in dense ground vegetation, in leaf litter or duff, grazed and ungrazed sites (Forsyth 2004, Hendricks 2012).