A Field Guide to the Snails of Lord Howe Island

118 Family Punctidae (Pinhead or Dot Snails) Allenella belli Iredale, 1944 Beautiful Pinhead Snail Shell. Size: H = 1.6 mm, D = 2.4 mm. Colour: Amber to golden. Shape: Depressedly turbinate with a low conical spire; sutures impressed; whorls rounded. Sculpture: Protoconch with spiral lirae; teleoconch with closely spaced, sinuate radial ribs and spiral lirae. Aperture: Ovately lunate. Umbilicus: Narrowly open. Animal. Not known. Key distinguishing features. Small discoidal shell with a low conical spire and distinct radial ribs. Habitat and occurrence. Upper slopes and summits of Mt Gower and Mt Lidgbird. Rare. Mostly known from dry shells found in leaf litter, but likely to be arboreal; the only known live specimens were collected in shrub beatings and from tree trunks. Remarks. Two subspecies have been described, A. belli belli from Mt Gower and A. belli extra from Mt Lidgbird. They have never been formally synonymised but are likely to represent a single species, so we do not include A. belli extra. Allenella formalis Iredale, 1944 Brown Turban Pinhead Snail Shell. Size: H = 2.5-2.6 mm, D = 3.4-3.6 mm. Colour: Amber to dark brown. Shape: Globosely turbinate with a moderately raised, conical spire. Sutures impressed. Whorls rounded above and below a slightly 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. Animal. Dark brown with slightly paler brown sole. Key distinguishing features. Largest species; more raised spire than congeners; dark brown body colour.