Passage 7.24.3
ἐφεξῆς δὲ τῷ Ὁμαγυρίῳ Διὶ Παναχαιᾶς ἐστι Δήμητρος. παρέχεται δὲ ὁ αἰγιαλός, ἐν ᾧ καὶ τὰ ἱερὰ Αἰγιεῦσίν ἐστι τὰ εἰρημένα, ὕδωρ ἄφθονον θεάσασθαί τε καὶ πιεῖν ἐκ πηγῆς ἡδύ. ἔστι δέ σφισι καὶ Σωτηρίας ἱερόν. ἰδεῖν μὲν δὴ τὸ ἄγαλμα οὐδενὶ πλὴν τῶν ἱερωμένων ἔστι, δρῶσι δὲ ἄλλα τοιαῦτα· λαμβάνοντες παρὰ τῆς θεοῦ πέμματα ἐπιχώρια ἀφιᾶσιν ἐς θάλασσαν, πέμπειν δὲ τῇ ἐν Συρακούσαις Ἀρεθούσῃ φασὶν αὐτά.
Next to Zeus Homagyrios is a temple of Panachaean Demeter. The seashore, on which stand the sanctuaries already mentioned that belong to the people of Aigion, provides abundant fresh water from a spring, pleasant both to see and to drink. They have also a sanctuary of Soteria (“Salvation”). The image there may be viewed by no one except the priests, and they observe other customs of this kind as well: when they receive from the goddess local cakes, they cast them into the sea, claiming that these are sent to Arethousa in Syracuse.