A variety of spiral shell from marine snails of the genus Cypraea, in which the opening is reduced to a slit running the length of one side. The humped, thick shell is beautifully colored (often speckled) and glossy; the apertural lips, which open into the first whorl in the shell, are rolled inward and may be fine-toothed. Its popularity in antiquity seems to depend on its use as a symbol of the female vulva. It was widely traded, larger species being imported into Europe from as far as the Red Sea. A cowrie-shaped amulet, known from Predynastic Egypt, was called a cowroid.