ARRIEGO, a department of France, bounded on the east by Auvergne, on the south-east by the Eastern Pyrenees, on the south by the mountains, and on the west and north by the department of the Upper Garonne. Its extent is 244 square miles, or 143,360 acres. It sends two deputies to the Chamber, is in the diocese of Pamiers, and within the jurisdiction of the royal tribunal of Toulouse. It contains three arrondissements, 20 cantons, and 330 communes. The population by the last returns appears to be 229,760 inhabitants. The chief towns are Tarascon, Aix, and Mirepoix.