Named for one of the three Gorgons. Medusa was mortal whereas the other two, Euryale and Stheno, were immortal. The eyes of the three Gorgons had the power of killing or turning onlookers into stone. Perseus killed Medusa, cut off her head, and placed it on the shield of Athena {see planet  (881)}, where it had the same petrifying power as when Medusa was alive. From the blood of Medusa sprang the winged horse Pegasus. (Z 161) _ _.