Arethusa (Arethu`sa) , a celebrated fountain in the island of Ortygia, near Syracuse, transformed from a Nereid pursued thither from Elis, in Greece, by the river-god Alphæus, so that the waters of the river henceforth mingled with those of the fountain.
Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)
Aretæ`us * Areti`no, Pietro