In the Greek mythology a class of nymphs who were fabled to lure the passing sailor to his ruin by the fascination of their music; Ulysses, when he passed the beach where they were sitting, had his ears stuffed with wax and himself lashed to the mast till he was at a safe distance from the influence of their charm. Orpheus, however, as he passed them in the Argonautic expedition so surpassed their music by his melodious notes, that in very shame they flung themselves into the sea and were changed into boulders.