Virginia Land Snails

Photo(s): An old shell of Helicodiscus hadenoecus found buried beneath the soil surface, typical for this possibly extirpated species in Virginia. Image by Ken Hotopp ©.

Click photo(s) to enlarge.

Helicodiscus hadenoecus Hubricht, 1962

Family: Helicodiscidae
Common name: Cricket Coil

Identification
Width: 2-3 mm
Height: 1-1.5 mm
Whorls: 4

The flattened, opaque shell of Helicodiscus hadenoecus has deep sutures and a microsculpture of spiral fringes upon its periostracum (outer protein coating). The fringes appear on both the top and base of the shell, excluding the embryonic whorl. The umbilicus is open and deep, about one-third the diameter of the entire shell. This shell lacks denticles or “teeth” within the aperture.

Ecology
Helicodiscus hadenoecus was initially described as a cave species, where it appears to feed on the guano of cave crickets in lightless zones(Hubricht, 1962; Lewis, 2005). In Tennessee it has been found in leaf litter and around logs (Coney et al, 1982). In Virginia it is found in rich forest habitats at the foot of bluffs along the New River, where shells are usually buried in 10 cm of soil or deeper (Hotopp, pers. obs.).

Taxonomy
There are no synonyms for this species’ name.

Distribution
This snail is known from Virginia, Kentucky, Tennessee, and Alabama. It has only been found as a subfossil in Virginia, where it is listed as possibly extirpated, and it is considered a vulnerable species in the other states.

NatureServe Global Rank: G3
NatureServe State Rank: SH

 

Ken Hotopp, Meegan Winslow 11/2012

Range Map