a circle in the Russian province of Volhynia. It is bounded on the north-west by Luzk, on the north-east by Rowno, on the east by Ostrog, on the south by Kremenez, and on the south-west by Austrian Galicia. It is the most fertile part of the rich province to which it belongs, is watered by the Slyr, and yields abundant crops of wheat, flax, tobacco, and rye. The capital, of the same name, is situated on the river Irwa. It is a large ill-built town, chiefly consisting of wooden houses, with crooked and ill-paved streets, and contains 5550 inhabitants, a great proportion of whom are Jews. Long. 25° 35' E. Lat. 50° 26' N.