Passage 2.16.7
νηπίους δὲ ἔτι ὄντας ἐπικατέσφαξε τοῖς γονεῦσιν Αἴγισθος--- καὶ Ἠλέκτρας · Πυλάδῃ γὰρ συνῴκησεν Ὀρέστου δόντος. Ἑλλάνικος δὲ καὶ τάδε ἔγραψε, Μέδοντα καὶ Στρόφιον γενέσθαι Πυλάδῃ παῖδας ἐξ Ἠλέκτρας. Κλυταιμνήστρα δὲ ἐτάφη καὶ Αἴγισθος ὀλίγον ἀπωτέρω τοῦ τείχους· ἐντὸς δὲ ἀπηξιώθησαν, ἔνθα Ἀγαμέμνων τε αὐτὸς ἔκειτο καὶ οἱ σὺν ἐκείνῳ φονευθέντες.
While still infants, Aegisthus slaughtered them upon the bodies of their parents—though Elektra was spared, and later lived with Pylades, whom Orestes had given her in marriage. Hellanicus further records that Pylades and Elektra had two sons, Medon and Strophius. Clytemnestra and Aegisthus were buried a little distance outside the city wall, as they were deemed unworthy of burial within the walls, where Agamemnon himself lay, together with those who were slain alongside him.