A Field Guide to the Snails of Lord Howe Island

30 Family Assimineidae (Palmleaf Snails) Limborelia innesi (Iredale, 1944) Compact Palmleaf Snail Shell. Size: H = 3.6-3.9 mm, D = 2.5-2.8 mm. Colour: Brown, appearing dark brown to black in live animals. Shape: Turbinate to conical with a pointed spire; whorls rounded with an angulate periphery; slight ridge above suture; sutures strongly impressed; whorls shouldered. Sculpture: Shell smooth, with microsculpture of fine incised spiral grooves. Aperture: Ovate with a slight basal point. Umbilicus: Narrowly open, half hidden by columella; circum- umbilical keel present. Animal. Body and cephalic tentacles black. Key distinguishing features. Smaller, less highly spired shell, angulate shell periphery, smooth shell surface with microsculpture only visible under magnification, circum-umbilical keel, black body; unique in living on rock faces rather than in leaf litter. Habitat and occurrence. Found on the southern mountains, in rainforest and moist woodland, on the slopes of Mt Lidgbird above 400 m (key locality Black Face) and on the southern slopes of Mt Gower, including Little Slope, Big Slope, Little Pocket and King Point. Found living on exposed rock faces. Remarks. Sympatric with L. exquisita on Little Slope and Big Slope, and with O. howeinsulae throughout its range. The disjunct Mt Gower population has been described as a separate subspecies ( Limborelia innesi adjecta ) but this is currently regarded as a synonym of L. innesi . 2 mm Limborelia innesi