Aethalides
A son of Hermes and Eupolemeia, a daughter of Myrmidon. He was the herald of the Argonauts, and had received from his father the faculty of remembering everything, even in Hades. He was further allowed to reside alternately in the upper and in the lower world.
As his soul could not forget anything even after death, it remembered that from the body of Aethalides it had successively migrated into those of Euphorbus, Hermotimus, Pyrrhus, and at last into that of Pythagoras, in whom it still retained the recollection of its former migrations. (Argonautica by Apollonius Rhodius)
From Smith's Dictionary of Greek and Roman Biography and MythologyFrom The Argonautica by Apollonius Rhodius
(ll. 51-56) Nor at Alope stayed the sons of Hermes, rich in corn-land, well skilled in craftiness, Erytus and Echion, and with them on their departure their kinsman Aethalides went as the third; him near the streams of Amphrysus Eupolemeia bare, the daughter of Myrmidon, from Phthia; the two others were sprung from Antianeira, daughter of Menetes.
