an arrondissement of the department of Isle Vilaine, in France, which is 593 square miles in extent, and is divided into seven cantons, and these into forty-six communes, containing 73,500 inhabitants. The capital is the city of the same name, situated on the river Vilaine. It is well built, and has a fine exchange, 710 houses, and 4120 inhabitants, with a considerable trade in serges and other woollen goods. Long 2° 11'. W. Lat. 47° 49'. N.