In Greek mythology, Ceryx or Keryx (English translation: "herald") was a son of Hermes and either Pandrosus[1] or Agraulus.[2] He was, like his father, a messenger of the gods.
According to Pausanias, he was the youngest son of Eumolpus,[2] one of the first priests of Demeter at Eleusis and a founder of the Eleusinian Mysteries.
He founded the two families of high priests in Eleusis: the Kerykes (or Kerukes, a family of priests in Athens) and the Eumolpidae.