A Field Guide to the Snails of Lord Howe Island

72 Family Charopidae (Pinwheel Snails) Genus Hedleyoconcha Pilsbry, 1893 Shell. Size: H = 5.6-6.9 mm, D = 7-10 mm. Colour: Pale golden-brown to greyish white, sometimes streaked with grey and white. Shape: Conical with a high spire; whorls rounded with a keeled periphery; sutures shallow. Sculpture: Protoconch smooth or with irregular pits; teleoconch smooth or with low to strong radial riblets and spiral cords. Aperture: Roundly to ovately lunate. Umbilicus: Moderately narrowly to very narrowly open, partially concealed by reflected lip. Habitat and occurrence. Mideastern NSW to northeastern Qld, including Lord Howe Island. Rainforest, living on trunks and leaves of trees and vines. Remarks. Differs from all other LHI charopids in its conical shape and keeled periphery. Two additional species, Hedleyoconcha delta and H. ailaketoae , are present on the eastern coast of Australia. Both species share with H. addita its conical shape with a high spire and keeled periphery, but differ in the presence of spiral and radial sculpture on the teleoconch, in having a much narrower umbilicus, and in the slightly larger size of H. delta . Both of the mainland Hedleyoconcha species are arboreal. Malabar Kim’s Lookout Transit Hill Intermediate Hill Mt Lidgbird Mt Gower ▲ ▲ ▲ ▲ ▲ ▲ ● H. addita