Glaucus fell in love with the Italian nymph Scylla, who rejected him. Thereupon he consulted the witch Circe, who herself became passionately fond of him. Since, however, he cared only for Scylla, Circe turned her into a monster from the waist down, with a row of dogs’ heads round her loins. Scylla went to live in a submerged cave on the Straits of Messina from which she preyed on passing sailors.