A Field Guide to the Snails of Lord Howe Island

60 Family Charopidae (Pinwheel Snails) The Charopidae is a Gondwanan group of small, primarily litter-dwelling snails found in Australasia, southern Africa, Central, South and western North America, the Pacific Islands and some subantarctic and south Atlantic Islands. It numbers around 700-800 described species worldwide, but total numbers are likely to be much greater, as these small and cryptic species are often poorly represented in collections. In south-eastern Australia, where the charopids are the most diverse family, over 200 species are currently recorded but true numbers are believed to exceed 500. Most charopids are minute to small (generally 1.5-7mm), but species with shells of 10-40 mm in diameter are known from Lord Howe Island, New Zealand and New Caledonia. Species are typically discoidal with a flattened, sunken or slightly raised spire, a simple lip, a lunate aperture usually lacking barriers, and a narrow to widely open umbilicus. Most charopids have a complex shell sculpture consisting of a combination of spiral cords and radial ribs, sometimes with periostracal extensions, with distinctly different sculpture on the protoconch and teleoconch. Shell colour ranges from cream to brown and can be uniform, banded or flammulated. Most charopids are litter-dwellers, being found under logs and rocks or sealed to leaves and debris, usually in rainforest. A few species are arboreal. Goweroconcha sp. Image: A. Moussalli.