Or Jasus, the name of a considerable number of mythical personages, which is sometimes written Iasius, and is etymologically the same as Iason and Iasion, though the latter is more especially used for the same persons as Iasius. Five persons of the name of lasus occur in the legends of Argos, viz. :--

1. A son of Phoroneus, and brother of Pelasgus and Agenor, or Arestor. (Eustath. ad Hom. p. 385.)

2. A son of Argus and Evadne, a daughter of Strymon, or, according to a scholiast (ad Eurip. Phoen. 1151), a son of Peitho, the father of Agenor, and father of Argus Panoptes. (Apollod. ii. 1. § 2.)

3. A son of Argus Panoptes and Ismene, the daughter of Asopus, and the father of Io. (Apollod. ii. 1. § 3.)

4. A son of Io. (Eustath. ad Hom. p. 1185.)

5. A son of Triopas, grandson of Phorbas, and brother of Agenor. This person is in reality the same as No. 3, with only a different pedigree assigned to him. (Paus. ii. 16. § 1; Hom. Od. xviii. 246; Eustath. ad Hom. p. 1465.)

6. An Arcadian, a son of Lycurgus and Cleophile or Eurynome, a brother of Ancaeus and Amphidamas, and the husband of Clymene, the daughter of Minyas, by whom he became the father of Atalante. (Apollod. iii. 9. § 2.) Hyginus (Fab. 70, 99) calls him Iasius, and Aelian (V. H. xiii. 1) and Pausanias (v. 7. § 4, 14. § 5) lasion. At the first Olympian games which Heracles celebrated, Iasus won the prize in the horse-race, and a statue of him stood at Tegea. (Paus. v. 8. § 1, viii. 4.)

7. A son of Eleuther, and father of Chaeresileus. (Paus. ix. 20. 2 )

8. The father of Amphion, and king of the Minyans. (Hom. Od. xi. 282; Paus. ix. 36, in fin.)

9. A son of Sphelus, the commander of the Athenians in the Trojan war, was slain by Aeneias. (Hom. Il. xv. 332, &c.)

10. The father of Dmetor, king of Cyprus. (Hom. Od. xvii. 443.)