Inferno (3.78), associate Charon with the river Acheron. Ancient Greek literary sources – such as Pindar, Aeschylus, Euripides, Plato, and Callimachus – also place Charon on the Acheron. Roman poets, including Propertius, Ovid, and Statius, name the river as the Styx, perhaps following the geography of Virgil's underworld in the Aeneid, where Charon is associated with both rivers. In ancient times some believed that a coin (Charon's obol) placed in the mouth of a dead person would pay the toll for the ferry across the river to the entrance of the Underworld. It was said that if someone could not pay the fee, they would never be able to cross the river. The ritual was performed by the relatives of the dead. According to the myth Narcissus is still admiring himself in the Underworld, looking at the waters of the Styx. The variant spelling Stix was sometimes used in translations of Classical Greek before the 20th century. By metonymy, the adjective stygian () came to refer to anything dark, dismal, and murky. Nymph Styx was the name of an Oceanid nymph, one of the three thousand daughters of the Titans Oceanus and his sister-wife Tethys, and the goddess of the River Styx. Others make her one of the progenies of the primordial gods, Nyx (Night) and Erebus (Darkness). In classical myths, Styx's husband was Pallas and she gave birth to Zelus, Nike, Kratos, and Bia (and sometimes Eos and Selene). Another source, adds Scylla, the Fontes (Fountains), and the Lacus (Lakes) as their children. Styx also mothered Echidna by Peiras and even Persephone by Zeus in one account. Mythology In these myths, Styx supported Zeus in the Titanomachy, where she was said to be the first to rush to his aid. For this reason, her name was given the honour of being a binding oath for the deities. Knowledge of whether this was the original reason for the tradition did not survive into historical records following the religious transition that led to the pantheon of the classical era. Moon On 2 July 2013, "Styx" officially became the name of one of Pluto's moons. The other moons of Pluto (Charon, Nix, Hydra, and Kerberos) also have names from Greco-Roman mythology related to the underworld. Gallery See also Gjöll - Norse mythology Hitpun - Mandaean mythology Hubur - Mesopotamian mythology Sanzu River - Japanese Buddhism Vaitarna River (mythological) - Hinduism and Buddhism