=Achil´les=, the son of Peleus and Thetis, was the bravest of all the Greeks in the Trojan war. During his infancy, Thetis plunged him in the Styx, thus making every part of his body invulnerable except the heel by which she held him. To prevent him from going to the Trojan war, Thetis sent him privately to the court of Lycomedes, where he was disguised in a female dress. As Troy could not be taken without his aid, Ulysses went to the court of Lycomedes in the habit of a merchant, and exposed jewels and arms for sale. Achilles, choosing the arms, discovered his sex, and went to the war. Vulcan made him a strong suit of armor, which was proof against all weapons. He was deprived by Agamemnon of his favorite Briseis, and for this affront he would not appear on the field till the death of Patroclus impelled him to vengeance. He slew Hector, who had killed Patroclus, and tying his corpse to his war-car, dragged it three times round Troy. He is said to have been killed by Paris, who inflicted a mortal wound in his vulnerable heel with an arrow. =A´cis.= A shepherd of Sicily, son of Faunus and the nymph Simæthis. Galatea passionately loved him, upon which his rival, Polyphemus, crushed him to death with a piece of broken rock. The gods changed Acis into a stream, which rises from Mount Etna. =Actæ´on.= A famous huntsman, son of Aristæus and Autonoe, daughter of Cadmus. He saw Diana and her attendants bathing, for which he was changed into a stag and devoured by his own dogs. =Ac´tium.= A town and promontory of Epirus, famous for the naval victory which Augustus obtained over Antony and Cleopatra, B. C. 31. =A´des or Hades.= The God of hell amongst the Greeks; the same as the Pluto of the Latins. The word is often used for hell itself by the ancient poets. =Adher´bal.= Son of Micipsa, and grandson of Masinissa, was besieged at Cirta, and put to death by Jugurtha, after vainly imploring the aid of Rome, B. C. 112. =Adme´tus.= Son of Pheres and Clymene, king of Pheræ in Thessaly. Apollo, when banished from heaven, is said to have tended his flocks for nine years. =Ado´nis=, son of Cinyras and Myrrha, was the favorite of Venus. He was fond of hunting, and was often cautioned not to hunt wild beasts. This advice he slighted, and at last was mortally wounded by a wild boar. Venus changed him into the flower anemone. Proserpine is said to have restored him to life, on condition that he should spend six months of the year with her, and the rest of the year with Venus. This implies the alternate return of summer and winter.