Charon, in Greek mythology, is the ferryman of the dead. The souls of the deceased are brought to him by Hermes, and Charon ferries them across the river Acheron. He only accepts the dead which are buried or burned with the proper rites, and if they pay him an obolus (coin) for their passage. For that reason a corpse had always an obolus placed under the tongue. Those who cannot afford the passage, or are not admitted by Charon, are doomed to wander on the banks of the Styx for a hundred years.
Charon ferries the dead across the river Acheron not the river Styx.