Passage 9.30.8
ῥεῖ δὲ καὶ ποταμὸς Ἑλικών· ἄχρι σταδίων ἑβδομήκοντα πέντε προελθόντι τὸ ῥεῦμα ἀφανίζεται τὸ ἀπὸ τούτου κατὰ τῆς γῆς· διαλιπὸν δὲ μάλιστα δύο καὶ εἴκοσι στάδια ἄνεισι τὸ ὕδωρ αὖθις, καὶ ὄνομα Βαφύρας ἀντὶ Ἑλικῶνος λαβὼν κάτεισιν ἐς θάλασσαν ναυσίπορος. τοῦτον οἱ Διασταὶ τὸν ποταμὸν ἐπιρρεῖν διὰ παντὸς τῇ γῇ τὰ ἐξ ἀρχῆς φασι· τὰς γυναῖκας δὲ αἳ τὸν Ὀρφέα ἀπέκτειναν ἐναπονίψασθαί οἱ θελῆσαι τὸ αἷμα, καταδῦναί τε ἐπὶ τούτῳ τὸν ποταμὸν ἐς τὴν γῆν, ἵνα δὴ μὴ τοῦ φόνου καθάρσια τὸ ὕδωρ παράσχηται.
The river Helicon also flows here. After advancing roughly seventy-five stadia, its stream disappears from sight, sinking beneath the ground. Then, after an interval of about twenty-two stadia, the water emerges again, now bearing the name Baphyras instead of Helicon, and flows on as a navigable river into the sea. The people of Dium declare that the river originally flowed continuously over the earth. However, when the women who had killed Orpheus sought to wash off his blood in its water, the river sank underground so that it might not cleanse them of their murder.