OLYNTHUS, a town in Macedouia, at the head of the Toronsie Gulf, was probably founded by the Chalcidians and Eretrians of Eubcea. (Strabo, x. p.447.) It was 60 stadia from Potidma, and was visible from the latter place. (Thug, i. 63.) It fell under the dominion of Athens, but revolted at the beginuing of the Peloponnesian war, and secured its independence with the aid of the Spartan Brasidas. From this time it was the most important of the towns of Chalcidice, and the head of a league. The jealousy of the Spartans subsequently made them attack the freedom of Olynthus, which became a depen dency of Sparta, ac. 379. After the Spartau supremacy had bet n overthrown by Eparninondes, the Olyuthians again recovered their independence. Philip of Macedonia viewed with jealousy the confede racy of the Olynihisurs but he made peace with them after his quarrel with the Athenians. In ac. 349 the Olynthians broke off their alliance with Philip, and sent to Athens for aaustanee. The Athenians, by the advice of Demosthenes, who advocated the cause of the Olynthians in his three Olynthire Orations, sent troops to their aid ; but the Olyn thians were defeated, and obliged to scirrender their town, which was destroyed by Philip lac 347.
OMA011, county Tyrone, Ireland, the maize town, and the seat of a Poor-Law Union, is situated on the left bank of the Stride, in 5f• 36' N. let., 7' 19' W. long., distant by road 34 miles S. from
Londonderry, and 110 miles N.N.W. from Dublin. The population in 1851 was 3335. Omagh Poor.Law Union comprises 29 electoral divisions, with an area of 174,214 acres, and a population in 1841 of 69,499; in 1351 of 56,302. In 169 a garrison loft in the place by James 11., on retiring, set fire to and almost completely destroyed the town. In 1743 it was laid waste by an accidental fire. It is now • clean, neat, and well-built town. The river is crossed by a handsome stone bridge. In the town are the parish church, and chapels for Roman Catholics, Rapti4a, Methodists, and Presbyterians; also several schools partially endowed. The county court house is an elegant building of Grecian architecture. Tho town contains the county jail (a large modern building), a new district lunatic asylum, the county infirmary, a foyer hospital, dispensary, and Union workhouse. Large sale* of corn and of brown linens are made at the weekly markets. Quarter and petty sessions are held. Fairs are held on the first Tuesday of every month ; Saturday is the market-day.
°MAC°. [lerntel OMAN. [Arts nIA. I