A Field Guide to the Snails of Lord Howe Island

119 Habitat and occurrence. Summits and upper slopes of Mt Lidgbird and Mt Gower. Remarks. This species is sympatric with congener A. belli , but can be distinguished by its larger size. Allenella planorum Iredale, 1944 Angular Pinhead Snail Shell. Size: H = 2.3 mm, D = 3.4 mm. Colour: Amber to light bronze. Shape: Turbinate with a low conical spire. Sutures impressed. Whorls rounded above and below an angulate periphery. Sculpture: Protoconch with spiral lirae; teleoconch with fine, closely spaced radial ribs or growth lines and fine spiral lirae. Aperture: Ovately lunate. Umbilicus: Narrowly open, partially obscured by reflected lip. Animal. Not known. Key distinguishing features. Slightly smaller than A. formalis , with a slightly narrower umbilicus and lower spire. Periphery more strongly angulate. Habitat and occurrence. Most common in the North Beach region and the settlement region. A few specimens are recorded from Intermediate Hill and the slopes of Mt Lidgbird. Remarks. This species was previously considered to be a subspecies of A. formalis, but was treated as a species by Stanisic et al. (2010). Allenella formalis