Passage 2.31.2
ἐν τούτῳ δέ εἰσι τῷ ναῷ βωμοὶ θεῶν τῶν λεγομένων ὑπὸ γῆν ἄρχειν, καί φασιν ἐξ Ἅιδου Σεμέλην τε ὑπὸ Διονύσου κομισθῆναι ταύτῃ καὶ ὡς Ἡρακλῆς ἀναγάγοι τὸν κύνα τοῦ Ἅιδου· ἐγὼ δὲ Σεμέλην μὲν οὐδὲ ἀποθανεῖν ἀρχὴν πείθομαι Διός γε οὖσαν γυναῖκα, τὰ δὲ ἐς τὸν ὀνομαζόμενον Ἅιδου κύνα ἑτέρωθι ἔσται μοι δῆλα ὁποῖα εἶναί μοι δοκεῖ.
In this temple there are altars of the gods who are said to rule beneath the earth. They say that Semele was brought up here from Hades by Dionysus, and that Heracles also brought up the hound of Hades. For my part, I cannot believe from the outset that Semele, being the wife of Zeus, ever died; as for the so-called hound of Hades, I will elsewhere make clear my own thoughts on the matter.