Apis
1. A son of Phoroneus by the nymph Laodice, and brother of Niobe. He was king of Argos, established a tyrannical government and called Peloponnesus after his own name but he was killed in a conspiracy headed by Thelxion and Telchin. (Apollodorus i. 6, ii. 1. § In the former of these passages Apollodorus states that Apis, the son of Phoroneus, was killed Aetolus; but this is a mistake arising from confusion of our Apis with Apis the son of Jason who was killed by Aetolus during the funeral games celebrated in honour of Azanes. (Pausanias)
Apis, the son of Phoroneus, is said, after his death, to have been worshipped as a god, under the name of Serapis; and this statement shews that Egyptian mythuses are mixed up with the story of Apis. This confusion is still more manifest in the tradition, that Apis gave his kingdom of Argos to his brother, and went to Egypt, where he reigned for several years afterwards. (Augustine's De Civitate Dei) Apis is spoken of as one of the earliest lawgivers among the Greeks. (Theodoret. Graec. Affect. Cur. vol. iv. p. 927, ed. Schulz.)
2. A son of Telchis, and father of Thelxion. He was king at Sicyon, and is said to have been such a powerful prince, that previous to the arrival of Pelops, Peloponnesus was called after him Apia. ( Pausanias Book 2)
Besides the third Apis, the son of Jason, mentioned above, there is a fourth, a son of Asclepius, mentioned by Aeschylus. (Suppl. 262.)
From Smith's Dictionary of Greek and Roman Biography and MythologyFrom The Mycenaean Origin of Greek Mythology By Martin P. Nilsson
The myth of the eponymous hero of the city of Argos is older, for it is mentioned in the Eoeae of Hesiod. To this Argos the deeds belong which are ascribed to Argus with the hundred eyes in Apollodorus. He killed a bull which ravaged Arcadia and put on its hide; he slew Satyrus, who robbed the herds of the Arcadians; he killed the sleeping Echidna, and he avenged the murder of Apis. The tendency appears clearly to make the eponymous hero of Argos rival Heracles, just as the Athenians created his rival in Theseus; but on the other hand these myths are clearly old, or they would not have been localized in Arcadia.