Passage 8.22.7
ἐν Στυμφάλῳ δὲ καὶ ἱερὸν Ἀρτέμιδός ἐστιν ἀρχαῖον Στυμφαλίας· τὸ δὲ ἄγαλμα ξόανόν ἐστι τὰ πολλὰ ἐπίχρυσον. πρὸς δὲ τοῦ ναοῦ τῷ ὀρόφῳ πεποιημέναι καὶ οἱ Στυμφαλίδες εἰσὶν ὄρνιθες· σαφῶς μὲν οὖν χαλεπὸν ἦν διαγνῶναι πότερον ξύλου ποίημα ἦν ἢ γύψου, τεκμαιρομένοις δὲ ἡμῖν ἐφαίνετο εἶναι ξύλου μᾶλλον ἢ γύψου. εἰσὶ δὲ αὐτόθι καὶ παρθένοι λίθου λευκοῦ, σκέλη δέ σφισίν ἐστιν ὀρνίθων, ἑστᾶσι δὲ ὄπισθε τοῦ ναοῦ.
At Stymphalus there is also an ancient sanctuary of Artemis Stymphalia; the statue is a wooden image, mostly overlaid with gold. Upon the roof of the temple are fashioned the Stymphalian birds; although it was difficult clearly to discern whether they were constructed of wood or plaster, by inference they appeared to us rather to be of wood than plaster. There are also here maidens carved from white marble, with the legs of birds, standing behind the temple.