(Ἀργυρᾶ), the nymph of a well in Achaia, was in love with a beautiful shepherd-boy, Selemnus, and visited him frequently, but when his youthful beauty vanished, she forsook him. The boy now pined away with grief, and Aphrodite, moved to pity, changed him into the river Selemnus. There was a popular belief in Achaia, that if an unhappy lover bathed in the water of this river, he would forget the grief of his love. (Paus. 7.23.2.)
[L.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890