Passage 2.18.3
ἀπὸ δὲ τῶν Κριῶν---οὕτω γὰρ τοῦ Θυέστου τὸ μνῆμα ὀνομάζουσι---προελθοῦσιν ὀλίγον ἐστὶν ἐν ἀριστερᾷ χωρίον Μυσία καὶ Δήμητρος Μυσίας ἱερὸν ἀπὸ ἀνδρὸς Μυσίου τὸ ὄνομα, γενομένου καὶ τούτου, καθάπερ λέγουσιν Ἀργεῖοι, ξένου τῇ Δήμητρι. τούτῳ μὲν οὖν οὐκ ἔπεστιν ὄροφος· ἐν δὲ αὐτῷ ναός ἐστιν ἄλλος ὀπτῆς πλίνθου, ξόανα δὲ Κόρης καὶ Πλούτωνος καὶ Δήμητρός ἐστι. προελθοῦσι δὲ ποταμός ἐστιν Ἴναχος, καὶ διαβᾶσιν Ἡλίου βωμός. ἐντεῦθεν δὲ ἐπὶ πύλην ἥξεις καλουμένην ἀπὸ τοῦ πλησίον ἱεροῦ· τὸ δὲ ἱερόν ἐστιν Εἰλειθυίας.
From the Rams—for this is what they call the tomb of Thyestes—a little further along, on the left, is a place called Mysia and a sanctuary of Demeter Mysia, named after a certain Mysius, who, according to the Argive tradition, was a host to Demeter. This sanctuary has no roof, but within it there stands another temple built of baked brick, containing wooden statues of Kore, Plouton, and Demeter. Going further onward, there is the river Inachus, and after crossing it, an altar to Helios. Beyond this altar, you arrive at a gate named from the nearby sanctuary; and this sanctuary is sacred to Eileithyia.