Pausanias Description of Greece 2.19.8

[8]
  Here are graves; one is that of Linus, the son of Apollo by Psamathe, the daughter of Crotopus; the other, they say, is that of Linus the poet. The story of the latter Linus is more appropriate to another part of my narrative, and so I omit it here, while I have already given the history of the son of Psamathe in my account of Megara . After these is an image of Apollo, God of Streets, and an altar of Zeus, God of Rain, where those who were helping Polyneices in his efforts to be restored to Thebes swore an oath together that they would either capture Thebes or die. As to the tomb of Prometheus, their account seems to me to be less probable than that of the Opuntians, ¹ but they hold to it nevertheless.

[8] Here are tombs; one is that of Linos, the son of Apollo by Psamathe, the daughter of Krotopos; the other, they say, is that of Linos the poet. The story of the latter Linos is more appropriate to another part of my narrative, and so I omit it here, while I have already given the history of the son of Psamathe in my account of Megara. After these is an image of Apollo, God of Streets, and an altar of Zeus, God of Rain, where those who were helping Polyneikes in his efforts to be restored to Thebes swore an oath together that they would either capture Thebes or die. As to the tomb of Prometheus, their account seems to me to be less probable than that of the Opuntians, but they hold to it nevertheless.