Land Snails

Photo(s): Shells of Triodopsis vulgata © Bill Frank (1) , and © Larry Watrous (3).

Click photo(s) to enlarge.

Triodopsis vulgata (Pilsbry, 1940)

Family: Polygyridae
Common name: Dished Threetooth

Identification
Width: 13.5-15 mm
Height: 7-10 mm
Whorls: 5+

One of many variations on the three-tooth theme, Triodopsis vulgata’s shell has a recessed outer (palatal) tooth. It has a heavy parietal tooth that is smaller than occurs in T. fraudulenta, a peg-like basal tooth, and the usual sculpture of tiny radial ridges over its shell. The umbilicus is open.

Ecology
Triodopsis vulgata prefers mature or late-successional, mesic forests, inhabiting ravines and wooded hillsides (Hubricht, 1985). In Tennessee it can be found on very steep slopes in leaf litter and woody debris (Coney et al, 1982).

Taxonomy
Synonyms for this species are Helix tridentata, H. fallax, Polygyra fraudulenta, Triodopsis fallax, and T. fraudulenta vulgata.

Distribution
From southern Michigan, southeastern Canada and New York in the north, T. vulgata’s range extends south in the Appalachians to Alabama, and west to Mississippi and Illinois (Pilsbry, 1940; Hubricht, 1985). In Virginia it is found mainly in the western counties.

Conservation
NatureServe Global Rank: G5
NatureServe State Rank: S3S4

 

Ken Hotopp, Meegan Winslow 11/2012

Range Map (click to enlarge)