Passage 2.33.2
Καλαύρειαν δὲ Ἀπόλλωνος ἱερὰν τὸ ἀρχαῖον εἶναι λέγουσιν, ὅτε περ ἦσαν καὶ οἱ Δελφοὶ Ποσειδῶνος· λέγεται δὲ καὶ τοῦτο, ἀντιδοῦναι τὰ χωρία σφᾶς ἀλλήλοις. φασὶ δὲ ἔτι καὶ λόγιον μνημονεύουσιν· ἶσόν τοι Δῆλόν τε Καλαύρειάν τε νέμεσθαι Πυθώ τʼ ἠγαθέην καὶ Ταίναρον ἠνεμόεσσαν. Unknown ἔστι δʼ οὖν Ποσειδῶνος ἱερὸν ἐνταῦθα ἅγιον, ἱερᾶται δὲ αὐτῷ παρθένος, ἔστʼ ἂν ἐς ὥραν προέλθῃ γάμου.
They say that Calaureia was originally sacred to Apollo, at the time when Delphi belonged to Poseidon, and it is also said that the two gods exchanged their territories. A prophetic utterance too is mentioned, which says: "Equal it is to possess Delos and Calaureia, And sacred Pytho and windy Taenarum." Now there is here a sacred sanctuary of Poseidon, and his priestess is a maiden until the time she reaches the proper age for marriage.