Hyginus
From Inachus and Argia Io. Jupiter loved and embraced Io, and changed her to heifer form so that Juno would not recognize her. When Juno found out, she sent Argus, who had gleaming eyes all around to guard her. Mercurius, at Jove’s command, killed him. But Juno sent a fearful shape to plague her, and out of terror of it she was driven wildly and compelled to cast herself into the sea, which is called Ionian. Thence she swam to Scythia, and the Bosporus is named from that; thence she went to Egypt where she bore Epaphus. When Jove realized that for his sake she had borne such suffering, he restored her to her own form, and made her a goddess of the Egyptians, called Isis. — 145