Apollodorus, Library and Epitome probably compiled in the first or second century AD (ed. Sir James George Frazer, 1921)

From the Library II. Lynceus reigned over Argos after Danaus and begat a son Abas by Hypermnestra; and Abas had twin sons Acrisius and Proetus by Aglaia, daughter of Mantineus. These two quarrelled with each other while they were still in the womb, and when they were grown up they waged war for the kingdom, and in the course of the war they were the first to invent shields. And Acrisius gained the mastery and drove Proetus from Argos; and Proetus went to Lycia to the court of Iobates or, as some say, of Amphianax, and married his daughter, whom Homer calls Antia, but the tragic poets call her Stheneboea. His in-law restored him to his own land with an army of Lycians, and he occupied Tiryns, which the Cyclopes had fortified for him. They divided the whole of the Argive territory between them and settled in it, Acrisius reigning over Argos and Proetus over Tiryns.

And Acrisius had a daughter Danae by Eurydice, daughter of Lacedaemon, and Proetus had daughters, Lysippe, Iphinoe, and Iphianassa, by Stheneboea. When these damsels were grown up, they went mad, according to Hesiod, because they would not accept the rites of Dionysus, but according to Acusilaus, because they disparaged the wooden image of Hera. In their madness they roamed over the whole Argive land, and afterwards, passing through Arcadia and the Peloponnese, they ran through the desert in the most disorderly fashion. But Melampus, son of Amythaon by Idomene, daughter of Abas, being a seer and the first to devise the cure by means of drugs and purifications, promised to cure the maidens if he should receive the third part of the sovereignty. When Proetus refused to pay so high a fee for the cure, the maidens raved more than ever, and besides that, the other women raved with them; for they also abandoned their houses, destroyed their own children, and flocked to the desert. Not until the evil had reached a very high pitch did Proetus consent to pay the stipulated fee, and Melampus promised to effect a cure whenever his brother Bias should receive just so much land as himself. Fearing that, if the cure were delayed, yet more would be demanded of him, Proetus agreed to let the physician proceed on these terms. So Melampus, taking with him the most stalwart of the young men, chased the women in a bevy from the mountains to Sicyon with shouts and a sort of frenzied dance. In the pursuit Iphinoe, the eldest of the daughters, expired; but the others were lucky enough to be purified and so to recover their wits. Proetus gave them in marriage to Melampus and Bias, and afterwards begat a son, Megapenthes.

When Acrisius inquired of the oracle how he should get male children, the god said that his daughter would give birth to a son who would kill him. Fearing that, Acrisius built a brazen chamber under ground and there guarded Danae. However, she was seduced, as some say, by Proetus, whence arose the quarrel between them; but some say that Zeus had intercourse with her in the shape of a stream of gold which poured through the roof into Danae's lap. When Acrisius afterwards learned that she had got a child Perseus, he would not believe that she had been seduced by Zeus, and putting his daughter with the child in a chest, he cast it into the sea. The chest was washed ashore on Seriphus, and Dictys took up the boy and reared him.

Polydectes, brother of Dictys, was then king of Seriphus and fell in love with Danae, but could not get access to her, because Perseus was grown to man's estate. So he called together his friends, including Perseus, under the pretext of collecting contributions towards a wedding gift for Hippodamia, daughter of Oenomaus. Now Perseus having declared that he would not stick even at the Gorgon's head, Polydectes required the others to furnish horses, and not getting horses from Perseus ordered him to bring the Gorgon's head. So under the guidance of Hermes and Athena he made his way to the daughters of Phorcus, to wit, Enyo, Pephredo, and Dino; for Phorcus had them by Ceto, and they were sisters of the Gorgons, and old women from their birth. The three had but one eye and one tooth, and these they passed to each other in turn. Perseus got possession of the eye and the tooth, and when they asked them back, he said he would give them up if they would show him the way to the nymphs. Now these nymphs had winged sandals and the kibisis, which they say was a wallet.

But all his back had on the head of a dread monster,
< The Gorgon,> and round him ran the kibisis. ”
Hesiod, Shield of Hercules, 223-4.

The kibisis is so called because dress and food are deposited in it. They had also the cap < of Hades>. When the Phorcides had shown him the way, he gave them back the tooth and the eye, and coming to the nymphs got what he wanted. So he slung the wallet (kibisis ) about him, fitted the sandals to his ankles, and put the cap on his head. Wearing it, he saw whom he pleased, but was not seen by others. And having received also from Hermes an adamantine sickle he flew to the ocean and caught the Gorgons asleep. They were Stheno, Euryale, and Medusa. Now Medusa alone was mortal; for that reason Perseus was sent to fetch her head. But the Gorgons had heads twined about with the scales of dragons, and great tusks like swine's, and brazen hands, and golden wings, by which they flew; and they turned to stone such as beheld them. So Perseus stood over them as they slept, and while Athena guided his hand and he looked with averted gaze on a brazen shield, in which he beheld the image of the Gorgon, he beheaded her. When her head was cut off, there sprang from the Gorgon the winged horse Pegasus and Chrysaor, the father of Geryon; these she had by Poseidon.

So Perseus put the head of Medusa in the wallet (kibisis ) and went back again; but the Gorgons started up from their slumber and pursued Perseus: but they could not see him on account of the cap, for he was hidden by it.

Being come to Ethiopia, of which Cepheus was king, he found the king's daughter Andromeda set out to be the prey of a sea monster. For Cassiepea, the wife of Cepheus, vied with the Nereids in beauty and boasted to be better than them all; hence the Nereids were angry, and Poseidon, sharing their wrath, sent a flood and a monster to invade the land. But Ammon having predicted deliverance from the calamity if Cassiepea's daughter Andromeda were exposed as a prey to the monster, Cepheus was compelled by the Ethiopians to do it, and he bound his daughter to a rock. When Perseus beheld her, he loved her and promised Cepheus that he would kill the monster, if he would give him the rescued damsel to wife. These terms having been sworn to, Perseus withstood and slew the monster and released Andromeda. However, Phineus, who was a brother of Cepheus, and to whom Andromeda had been first betrothed, plotted against him; but Perseus discovered the plot, and by showing the Gorgon turned him and his fellow conspirators at once into stone. And having come to Seriphus he found that his mother and Dictys had taken refuge at the altars on account of the violence of Polydectes; so he entered the palace, where Polydectes had gathered his friends, and with averted face he showed the Gorgon's head; and all who beheld it were turned to stone, each in the attitude which he happened to have struck. Having appointed Dictys king of Seriphus, he gave back the sandals and the wallet (kibisis ) and the cap to Hermes, but the Gorgon's head he gave to Athena. Hermes restored the aforesaid things to the nymphs and Athena inserted the Gorgon's head in the middle of her shield. But it is alleged by some that Medusa was beheaded for Athena's sake; and they say that the Gorgon was fain to match herself with the goddess even in beauty.

Perseus hastened with Danae and Andromeda to Argos in order that he might behold Acrisius. But he, learning of this and dreading the oracle, forsook Argos and departed to the Pelasgian land. Now Teutamides, king of Larissa, was holding athletic games in honor of his dead father, and Perseus came to compete. He engaged in the pentathlum, but in throwing the quoit he struck Acrisius on the foot and killed him instantly. Perceiving that the oracle was fulfilled, he buried Acrisius outside the city,3 and being ashamed to return to Argos to claim the inheritance of him who had died by his hand, he went to Megapenthes, son of Proetus, at Tiryns and effected an exchange with him, surrendering Argos into his hands. So Megapenthes reigned over the Argives, and Perseus reigned over Tiryns, after fortifying also Midea and Mycenae.