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Family: Gastrodontidae
Common name: Sculptured Dome
Discovery: Pilsbry, 1896
Identification
Width: 8.4 – 9.6 mm
Height: 6.0 – 8.1 mm
Whorls: 7.5
The thickness of Ventridens collisella’s shell and its sharp irregular striations above help set it apart from similar Ventridens, along with the tiny size of the half-covered umbilicus. Its apex is dome-shaped and elevated, and the base is rather flat. The shell is smoother on the base, but still faintly wrinkled and spirally striate. The lip of the aperture is thin, but wider where it meets the columella. There are usually two lamellae, one close to the columellar insertion the other basal and a bit recessed. These are sometimes absent (Pilsbry, 1946). The animal is light-colored.
Ecology
This species is a calciphile. It is found in leaf litter on hillsides and in steep valleys (Hubricht, 1985). In Tennessee it is associated with very steep slopes, leaf litter, neutral soils, and with late-successional forests (Coney et al, 1982). Hubricht (1985) reports that it occurs primarily at lower elevations, usually below 1,000 feet, while Coney et al (1982) found it correlated with “high” elevation in Tennessee (940-1,120’).
Taxonomy
Synonyms for V. collisella are Gastrodonta collisella and Zonitoides (Ventridens) collisella.
Distribution
Ventridens collisella is a southern mountain species. Its range begins in the upper corners of Georgia and Alabama where the two states meet, and extends up through Kentucky into Virginia and West Virginia. It is not found in central or eastern parts Virginia.
Conservation
NatureServe Global Rank: G4
NatureServe State Rank: S4
