Pausanias Description of Greece 2.3.7

[7] And, since their death was violent and unjust, the infant offspring [ nēpia tekna] of the Corinthians kept on being destroyed by them [= the ghosts of the children of Medea] until, in accordance with what the god [= Apollo] said-as-an-oracular-pronouncement [ khrēsai], yearly sacrifices [ thusiai] were established in their honor and a figure of Terror [ Deima] was set-up-in-compensation [ epi-stēnai]. This figure still exists, even in my time: it is the image [ eikōn] of a woman rather frightful to look at. After Corinth was destroyed by the Romans and the old Corinthians were wiped out, the new settlers no longer observed the custom of offering those sacrifices [ thusiai] to the sons of Medea, nor do their children [who are initiated into the hero cult of the children of Medea] cut their hair for them or wear black clothes.