in fabulous history, one of the three Gorgons, daughter of Phoreys and Ceto. She was the only one of the Gorgons who was subject to mortality. She is celebrated for her personal charms and the beauty of her locks. Neptune became enamoured of her, and obtained her favours in the temple of Minerva. This violation of the sanctity of the temple provoked Minerva; and she changed the beautiful locks of Medusa, which had inspired Neptune's love, into serpents, the sight of which turned the beholders into stones; but Perseus, armed with Mercury's axe, with which he killed Argus, cut off Medusa's head, from whose blood sprang Pegasus and Chrysaor, together with the innumerable serpents. serpents that infest Africa. The conqueror placed Medusa's head on the aegis of Minerva, which he had used in his expedition; and the head still retained the same petrifying powers as before.

a genus of vermes, belonging to the order of mollusca. See HELMINTHOLOGY Index.