Image Usage Information
Family: Polygyridae
Common name: Upland Pillsnail
Discovery: Say, 1824
Identification
Width: 9.0 -10.5 mm
Height: 5-7 mm
Whorls: 5+
Euchemotrema fraternum is well-protected against predators, with a thick, round-ish, crush-resistant shell, and a narrow aperture. The shell is covered with fine bristles that may help to camouflage it with a dull, non-reflective texture, and by trapping dust and cobwebs. The aperture holds a single blade-like tooth, or lamella. The reflected lip nearly covers the umbilicus. Live Euchemotrema fraternum are dark brown or dark gray above.
This species is distinguished from E. leai by being more densely hairy, and by having a slit-like umbilicus, while the umbilicus of E. leai is approximately half to two-thirds covered.
Ecology
This animal inhabits relatively higher sites than its close relative Euchemotrema leai. It is a good climber for its small size, sometimes found on maple or beech trunks. It is most often encountered in leaf litter and log debris, and usually at low densities.
Taxonomy
Euchemotrema fraternum has also been known as Helix fraterna, H. convexa, H. monodon, Polygyra fraterna, P. f. var. albida, P. monodon fraternal, and S. monodon.
Distribution
Euchemotrema fraternum occurs from the Midwest and Middle Atlantic states, north to Minnesota and the Canadian Maritimes and south to Louisiana and Mississippi (Hubricht, 1985). In Virginia it is found in western and northern counties.
Conservation
NatureServe Global Rank: G5
In northern Maine this species seems to have declined significantly over the past century and is now uncommon (Nikola, 2008; Hotopp, pers. obs.).
