Lewis Short
Aethra (noun F) : Αἴθρα.
* Daughter of Oceanus and Tethys, mother of Hyas (in Hyg. Fab. 192 called Pleione), Ov. F. 5, 171.
* Daughter of Piltheus and motherof Theseus, acc. to Ov. H. 10, 131, and Hyg. Fab. 37.
Charlton T. Lewis, Charles Short, A Latin Dictionary