A Field Guide to the Snails of Lord Howe Island

147 Family Helicidae The Helicidae is a large family native to Europe, central Asia, the Middle East and North Africa, with several species that have become established worldwide. Species are medium to very large, with shells ranging from globose to discoidal with rounded to keeled whorls. Shell colour is variable both within and between species, and can be unicoloured or patterned with bands, speckles or flammulations. Most species are herbivorous and feed on living plants. Like bradybaenids, helicids fire calcified darts as part of their courtship. Eleven helicid species have been introduced into Australia, but only one is found on Lord Howe Island. Cornu aspersum (Müller, 1774) Common Garden Snail Shell. Size: H = 24.3-28 mm, D = 25.9-32.5 mm. Colour: Brown with darker spiral bands and yellow-brown radial flammulations and speckles; inner part of lip white. Shape: Globose with an elevated spire; whorls rounded; sutures weakly impressed. Sculpture: Malleated. Aperture: Roundly lunate; lip reflected. Umbilicus: closed. Animal. Body greenish brown to grey. Key distinguishing features. Large, globose, brown-patterned shell. Habitat and occurrence. First recorded on Lord Howe Island in 1967 and only known from the Settlement region, in relatively disturbed habitats. This introduced European species is widespread in Australia and worldwide. Remarks. This species is the largest introduced snail on the island. Cornu aspersum 10 mm