Land Snails

Euconulus polygyratus (Pilsbry, 1899)

Photo(s): Shell of Euconulus polygyratus images © Michál Horsák and Veroniká Horsáková

Click photo(s) to enlarge.

Family: Euconulidae
Common name: Fat Hive

Identification
Width: 2.7-3.4 mm
Height: 2.3-2.8 mm
Whorls: 6+

The shell of Euconulus polygyratus is stout and wide, globosely conic, with tight whorls and a simple lip (Pilsbry, 1946). The shell is amber to brown with a silky surface texture. The final whorl of adult shells is well-rounded, while immature shells are more angular and difficult to identify. The shell is more tightly whorled, rounder and less glossy than E. fulvus, and relatively wider than E. chersinus.

Ecology
Euconulus polygyratus is a litter-dweller like its congeners. In northern Maine it is sparsely distributed but appears to favor habitats richer in calcium (from Nekola, 2008).

Taxonomy
Taxonomy of the Euconulus is in a state of flux. Genetics work in progress suggests E. polygyratus is a unique species (J.C. Nekola, pers. comm. 2/26/2018). Synonyms for E. polygyratus include E. chersinus polygyratus and Conulus chersinus polygyratus (Pilsbry, 1946).

Distribution
Euconulus polygyratus is found across the upper Midwest of the United States and Canada, east to New England and the Canadian Maritimes, and south in the Appalachian Mountains. It appears to be mistakenly identified as E. fulvus by Hubricht (1985) in the region’s southernmost states (J.C. Nekola, pers. comm. 2/26/2018).

Conservation
NatureServe Global Rank: G5, Secure.

Ken Hotopp 3/2018

Range Map (click to enlarge)