Hermione's exemption from Charon's ferry-fee.
Plouton fell in love with Persephone and with the help of Zeus carried her off secretly. But Demeter went about seeking her all over the earth with torches by night and day, and learning from the people of Hermione that Plouton had carried her off, she was wroth with the gods and quitted heaven, and came in the likeness of a woman to Eleusis. — Apollodoros 1.5.1 (cf. Zenobios. Cent. 1.7; Schol. Aristoph. Kn. 785)
It is commonly reported that there is a shortcut to the descent to Hades in the land of the Hermionians; and this is why they do not place the ferry-fee in the mouths of their dead. — Strabo 8.6.12.
Porthmeion: the pay of a sailor. Kallimachos [writes]: "therefore even as corpses they do not carry the boat-fare ." For at Aigialos (Sea-shore) there is a way down to Hades, which Demeter came to and learned from the locals about Kore and, as he says, granted them exemption from the boat-fare. — Suda s.v. Πορθμήϊον (Π2072)
Danakēs: this is the name of a foreign coin, worth more than an obol, which they placed in the mouths of the dead. Kallimachos [writes]: “Therefore only in this city corpses do not carry the ferryman's fee, which by custom others carry in their desiccated mouths.” The danakēs is the ferry-fee of the Acherousian ship. Acherousia is a lake in Hades, which the dead cross, and as they do so they give the aforementioned coin to the ferryman. — Et. Gen. AB s.v. δανάκης (Kallimachos F 278 Pfeiffer)
(4) The object most worthy of mention is a sanctuary of Demeter on Pron. This sanctuary is said by the Hermionians to have been founded by Klymenos, son of Phoroneos, and Chthonia, sister of Klymenos. But the Argive account is that when Demeter came to Argolis, while Atheras and Mysios afforded hospitality to the goddess, Kolontas neither received her into his home nor paid her any other mark of respect. His daughter Chthonia disapproved of this conduct. They say that Colontas was punished by being burnt up along with his house, while Chthonia was brought to Hermion by Demeter, and made the sanctuary for the Hermionians. (5) At any rate, the goddess herself is called Chthonia, and Chthonia is the name of the festival they hold in the summer of every year. The manner of it is this ... [there follows an amazing description of the festival] (9) There is also another temple, all round which stand statues. This temple is right opposite that of Chthonia, and is called that of Klymenos, and they sacrifice to Klymenos here. I do not believe that Klymenos was an Argive who came to Hermion “Klymenos” is the surname of the god, whoever legend says is king in the underworld. (10) Beside this temple is another; it is of Ares, and has an image of the god, while to the right of the sanctuary of Chthonia is a portico, called by the natives the Stoa of Echo. It is such that if a man speaks it reverberates at least three times. Behind the temple of Chthonia are three places, which the Hermionians call that of Klymenos, that of Plouton, and the Acherousian Lake. All are surrounded by fences of stones, while in the place of Klymenos there is also a chasm in the earth. Through this, according to the legend of the Hermionians, Herakles brought up the hound of Hades. — Paus. 2.35.4-10. Presumably the chasm was also the place where local myth said Demeter was shown the site of Persephone's abduction.