Land Snails

Photo(s): Mesodon zaletus © Bill Frank, shell views © Larry Watrous.
Illustrations © Kathy Schmidt from her series "Land Snails of New York State."

Click photo(s) to enlarge.

Mesodon zaletus (A. Binney, 1837)

Family: Polygyridae
Common name: Toothed Globe

Identification
Width: 24-27 mm
Height: 17-25 mm
Whorls: 5+

This snail’s shell is the largest of those that have a single parietal tooth (on the body whorl). That lamella can be quite small. The shell of Mesodon zaletus is relatively rounded and sturdy. The aperture lip is reflected and the umbilicus is closed. It is apparently a long-lived species and older shells may be whitish, especially at the apex, having lost the brown outer coating called the periostracum.

Ecology
Mesodon zaletus is a denizen of cool hardwood or mixed forests, often inhabiting steep slopes, especially along rivers. It may be found in leaf litter and occasionally in moss. Some of these animals can reach high elevations, living up to 5,000’ (Hubricht, 1985). In Tennessee, it has been associated with limestone areas in late-successional forests (Coney et al., 1982).

Taxonomy
Synonyms for M. zaletus include: Helix albolabris var. unidentata, H. exoleta, H. zaleta, Mesodon andrewsi, M. exoleta, and Polygyra zaleta.

Distribution
The range of M. zaletus extends from New York, southern Ontario and Michigan, to east Texas and northern Alabama. In Virginia this snail is found in the western counties on the West Virginia and Kentucky border.

Conservation
NatureServe Global Rank: G5, Secure
NatureServe State Rank: Pennsylvania, S4S5, Apparently Secure; Virginia, S3S4, Vulnerable to Apparently Secure; otherwise unlisted in Northeastern States.

 

Ken Hotopp, Meegan Winslow 9/2012

Range Map (click to enlarge)