Perrona spirataPerrona spirata is a species of sea snail, a marine gastropod mollusk in the family Clavatulidae.DescriptionThe size of an adult shell varies between. The whorls are constricted around the upper part, with a rather sharp ridge next to the suture, and an obtuse angle below the constriction. The color of the shell is yellowish, mottled and striped with chestnut.