snails gastropod molluscs which have an external enclosing spiral shell, especially the land snails in the genus Helix. (There are both land and marine snails, but the name snail by itself is usually taken to indicate the former.) The many different edible varieties of these include some which have been cultivated since earliest times. H. salomonica was eaten in ancient Mesopotamia. Ucko and Dimbleby (1969) believe that the Romans domesticated a species of large snail, probably H. pomata, keeping them in special vivaria and breeding for such characters as size, colour, and fecundity.