Virginia Land Snails
Photo(s): Mesomphix subplanus by Bill Frank ©, shell by Dan Dourson ©.
Click photo(s) to enlarge.
Mesomphix subplanus (A. Binney, 1842)
Common name: Flat Button
Width: 16.0 – 22.3 mm
Height: 6.0 – 10.6 mm
The shell of Mesomphix subplanus is similar in overall plan to many other Mesomphix, but looks as if it has been squeezed in a press. The umbilicus is tiny and is only somewhat indented from the base, which is quite flat, and the apex is also flattened. The shell is thin, and the lip of the aperture is simple and thin. The glossy shell may vary in color, being olive or brown, and it is has radial striations.
This species is found at higher altitudes, 2,000 feet or above, in moist leaf litter and around logs (Hubricht, 1985).
Synonyms for M. subplanus are: Helix sub-plana, Mesomphix subplana, M. subplanus planus, Omphalina subplana, and Zonites subplanus.
Mesomphix subplanus has a range similar to that of M. rugeli, though even more limited. It is found mostly along the North Carolina/Tennessee line. It appears in a cluster of counties on the southern Virginia border intersection where the three states meet.
NatureServe Global Rank: G3G4
NatureServe State Rank: S2
Virginia’s wildlife action plan: Tier III
Greg Kimber, Ken Hotopp 11/2012