Virginia Land Snails

Photo(s): Mesodon andrewsae showing some variation in body color, image by Bill Frank ©.

Click photo(s) to enlarge.

Mesodon andrewsae W.G. Binney, 1879

Family: Polygyridae
Common name: Balsam Globe

Width: 21-25 mm
Height: 15-18 mm
Whorls: 5+

The shell of Mesodon andrewsae is rounded and extremely thin, with tiny radial striae. The final whorl is very large in comparison to the others, and it alone comprises about half of the snail’s overall size. There are typically no denticles in the wide, slightly reflected aperture, although some forms may have a small parietal tooth. It is typically an olive-green color, though some forms are reddish, or may have a reddish band above the periphery (Hubricht, 1985).

Mesodon andrewsae inhabits high mountains above 2,000’.

Synonyms for M. andrewsae include: Mesodon andrewsae intermedius, M. andrewsi, and Polygyra andrewsae.

This southern Appalachian Mountain endemic was previously reported from West Virginia to Tennessee and North Carolina (Hubricht, 1985). However, in the Great Smoky Mountains the former subspecies M. a. altivagus has been elevated to species level (Emberton, 1991), so it is unclear whether its current range still includes these southernmost counties. In fact, there remains uncertainty about the distinction between M. andrewsae and M. altivagus (Emberton, 1991), and between M. andrewsae and the more widespread southeastern species M. normalis (Pilsbry, 1900; previously M. andrewsae normalis).

In Virginia, Mesodon andrewsae is reported only from Grayson and Smith Counties.

NatureServe Global Rank: G3
NatureServe State Rank: S1
Virginia’s wildlife action plan: Tier II


Meegan Winslow, Ken Hotopp 9/2012

Range Map