Powelliphanta superba is a species of large, carnivorous land snail in the family Rhytididae, which is endemic to the South Island of New Zealand. Five subspecies are recognised, all of which are classified by the New Zealand Department of Conservation as being Nationally Endangered. \n* Powelliphanta superba harveyi \n* Powelliphanta superba mouatae \n* Powelliphanta superba prouseorum \n* Powelliphanta superba richardsoni \n* Powelliphanta superba superba The eggs are oval and seldom constant in dimensions 14 by 12 millimetres (0.55 in × 0.47 in).