Arcas
1. The ancestor and eponymic hero of the Arcadians, from whom the country and its inhabitants derived their name. He was a son of Zeus by Callisto, a companion of Artemis. After the death or the metamorphosis of his mother, Zeus gave the child to Maia, and called him Arcas. (The Theogony of Apollodorus III) Arcas became afterwards by Leaneira or Meganeira the father of Elatus and Apheidas. (The Theogony of Apollodorus III)
According to Hyginus (Fab. 176, Poet. Astr. ii. 4) Arcas was the son of Lycaon, whose flesh the father set before Zeus, to try his divine character. Zeus upset the table which bore the dish, and destroyed the house of Lycaon by lightning, but restored Arcas to life.
When Arcas had grown up, he built on the site of his father's house the town of Trapezus.
When Arcas once during the chase pursued his mother, who was metamorphosed into a she-bear, as far as the sanctuary of the Lycaean Zeus, which no mortal was allowed to enter, Zeus placed both of them among the stars, (From Metamorphoses ii. 410, &c.) According to Pausanias (Description of Greece by Pausanias. viii. 4. § 1, &c.), Arcas succeeded Nyctimus in the government of Arcadia, and gave to the country which until then had been called Pelasgia the name of Arcadia. He taught his subjects the arts of making bread and of weaving. He was married to the nymph Erato, by whom he had three sons, Elatus, Apheidas, and Azan, among whom he divided his kingdom. He had one illegitimate son, Autolaus, whose mother is not mentioned. The tomb of Arcas was shewn at Mantineia, whither his remains had been carried from mount Macnalus at the command of the Delphic oracle. (Description of Greece by Pausanias viii. 9. § 2.) Statues of Arcas and his family were dedicated at Delphi by the inhabitants of Tegea. (x. 9. § 3.)
2. A surname of Hermes. (Pharsalia or Civil War by Lucanus)
From Smith's Dictionary of Greek and Roman Biography and Mythology