Land Snails

Photo(s): Views of a Paravitrea septadens shell. Note the base of the transverse lamella inside the final whorl at the two o’clock position. Images © Ken Hotopp.

Click photo(s) to enlarge.

Paravitrea septadens (Hubricht, 1978)

Family: Pristilomatidae
Common name: Brown Supercoil

Identification
Width: 3-4 mm
Height: 1.5-2 mm
Whorls: 6+

The spire of Paravitrea septadens is very low, causing the shell to appear nearly disk-shaped. Irregularly-spaced radial growth lines mark the later whorls; lines are less distinct on the base of the shell, and the nuclear whorl is smooth. The umbilicus is narrow, deep and well-like. The whorls slowly increase in size, expanding somewhat abruptly near the aperture in older shells. The final whorl usually contains a radial lamella, sometimes two, visible through the translucent base of the shell.

Ecology
Paravitrea septadens is found on steep forested slopes and in ravines, often among woody debris, rocks, or deeper leaf litter. It is found in mixed eastern hemlock-hardwood forest, and also in richer hardwood stands (Hotopp, per obs). It is frequently found together with P. multidentata (Hubricht, 1985).

Taxonomy
There are no synonyms.

Distribution
Paravitrea septadens is known only from Dickenson and Buchanan Counties, Virginia (Hubricht, 1985), and adjacent Pike County, Kentucky (Dourson, 2010).

Conservation
NatureServe Global Rank: G1
NatureServe State Rank: S1
State Status: Threatened
Virginia’s wildlife action plan: Tier I

 

Ken Hotopp, Meegan Winslow 11/2012

Range Map (click to enlarge)