Hystricella bicarinata
Hystricella bicarinata is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Hygromiidae, the hairy snails and their allies. Two subspecies are recognised, one extant and one known only as a fossil. This species is endemic to the island of Porto Santo in the Madeira archipelago, Portugal. They are terrestrial and are found under rocks in grasslands. They have a very limited range, confined to about ten square kilometers but are abundant within that area.