A Field Guide to the Snails of Lord Howe Island

35 Family Diplommatinidae (Staircase-Snails) Genus Palaina Semper, 1865 (Description based on Lord Howe Island species only.) Shell. Size: H = 1.5-6.3 mm, D = 0.9-3.5 mm. Colour: Pale golden- to orange-brown to white, sometimes with a white peripheral band on last whorl. Shape: Pupiform, with a conical to domed spire; shell coiled sinistrally. Sculpture: Axial ribs, ranging from fine and closely spaced to strong and broadly spaced. Rib spacing is often closer on the last 1-2 whorls. Aperture: Usually circular with a reflected lip; occasionally ovate. Umbilicus: Closed. Operculum: Present. Animal. Head with a broad, expandable snout; eyes at bases of long, thin cephalic tentacles. Where known, body is white, with black eyes and dark grey cephalic tentacles. Habitat and occurrence. Widespread across Lord Howe Island; also distributed on islands in the Pacific Ocean and the Papuan and Wallacean regions. Remarks. Palaina is a large genus with 145 recognised species. The type species of the genus is the Lord Howe Island endemic P. macgillivrayi . Malabar Kim’s Lookout Transit Hill Intermediate Hill Mt Lidgbird Mt Gower ▲ ▲ ▲ ▲ ▲ ▲ ● ●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●●●●●● ● ●● ●●●● ●●● ●●●● ●●●●●●●●●● ●● ● ● ●●●● ●●●● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ●●● ●●● ● ● ●●●● ●● ● ● ● ● ●● ● ● ●●● ●●●●●● ●●●●●●●●●●●● ● ● ● ● ●● ● P. arborfumosa ● P. macgillivrayi