Edwin Sidney Hartland 
The legend of Perseus, Volume III [EPUB ebook] 
Andromeda. Medusa.

We have traced the incidents of the Supernatural Birth and the Life-token throughout the world: the two remaining incidents of the Rescue of Andromeda and the Medusa-witch have a more restricted range. For though traditions of a fight with a monster and of human beings turned to stone, the germs of the incidents in question, are almost universal, yet the special forms evolved from these germs in the Perseus saga seem to be confined to the Eastern Continent, save where immigrant peoples have taken them in modern times to the New World and given them in some rare instances currency there among the aboriginal tribes.