Virginia Land Snails
Photo(s): A Discus nigrimontanus shell exhibits slightly “tilted” whorls, by Larry Watrous ©.
Click photo(s) to enlarge.
Discus nigrimontanus (Pilsbry, 1924)
Common name: Black Mountain Disc
Width: 7.4 mm
Height: 2.4 mm tall
The shell of Discus nigrimontanus looks flattened when seen from the side, with a low apex and a shallow, open umbilicus. The top of the whorls are bluntly angled, with the bottom even more blunt and sloping inward slightly. The shell is covered with coarse radial ribbing and it has a thin lip, as in most of its relatives. This species is similar in some ways to D. bryanti, though D. nigrimontanus’ whorls are not as sharply angled.
Discus nigrimontanus is usually found in thin leaf litter in rocky upland woods (Hubricht, 1985).
It has reportedly hybridized with D. patulus, giving rise to the form edentulus common in Arkansas (Hubricht, 1985). A synonym for this species is Gonyodiscus bryanti nigrimontanaus.
This species has been reported in Alabama, Arkansas, Kentucky, Missouri, North Carolina, Tennessee, and Virginia. In Virginia it has been found only in the westernmost parts, in Grundy and Russell counties.
NatureServe Global Rank: G4
NatureServe State Rank: S1S3
Virginia’s wildlife action plan: Tier IV
Greg Kimber, Ken Hotopp 7/2012Range Map