Virginia Land Snails
Photo(s): A shell of Helicodiscus notius by Jeffrey C. Nekola ©.
Click photo(s) to enlarge.
Helicodiscus notius Hubricht, 1962
Common name: Tight Coil
Width: 3-4 mm
Height: 1.5-2.0 mm
Helicodiscus notius has a shallow, open umbilicus, nearly half the diameter of its entire shell. Spiral lirae decorate the surface of the shell, including the embryonic whorl. Two cone-shaped teeth may usually be found on the basal wall of the final whorl and two on the outer wall. Sometimes a third pair of teeth may be present. As a juvenile, the disk-like shell of Helicodiscus notius is translucent; as a mature adult, it is opaque. The sutures are deep.
Compared with Helicodiscus parallelus, H. notius prefers drier habitats. It may be found around logs and in the leaf litter of late-stage forests and occasionally in caves, but only where leaf litter has been washed or blown in (Hubricht, 1962). In Tennessee it has been noted in close association with limestone substrata (Coney et al, 1982).
This species’ shell is not clearly distinguishable from Helicodiscus parallelus or H. shimeki and its described characters are so subtly different as to raise questions about its taxonomic validity. This species is also known as Helicodiscus notius notius.
Helicodiscus notius is reported throughout the Southeastern and Central United States. Virginia represents its northeastern boundary.
NatureServe Global Rank: G5Q
NatureServe State Rank: SNR
Meegan Winslow, Ken Hotopp 11/2012Range Map