Powelliphanta augusta or the Mount Augustus snail, previously provisionally known as Powelliphanta 'Augustus', is a species of large, carnivorous land snail, a terrestrial pulmonate gastropod mollusc in the family Rhytididae. Naturally occurring only on Mount Augustus near Westport on New Zealand's South Island, their entire habitat was destroyed by coal mining. The world population was taken into captivity, in theory until their habitat was restored and they could be released. The mining company concerned went bankrupt and habitat restoration has been unsuccessful, so the species' future is uncertain. The species is endemic to the South Island of New Zealand. It was found only on the Mount Augustus ridgeline northeast of Westport, which has since been removed by mining operations of the state-owned company Solid Energy. The species was first discovered in 1996 by members of the Nelson Botanical Society, however, the Department of Conservation was unaware of its existence until 2004. Department of Conservation scientists initially thought that there appeared to be less than 1,000 of these snails.