an arrondissement of the department of the Landes, in France, extending over 918 square miles. It is divided into eight cantons, and subdivided into 112 communes, containing 87,000 inhabitants. The capital, of the same name, is situated on the river Adour. It is fortified, and defended by a strong castle, and contains 1046 houses, with 4398 inhabitants. It is celebrated for a warm spring in the centre of the town, which is used for bathing as well as for drinking. Some trade in products of the soil is carried on through Bayonne. Long. 1. 9. 1. W. Lat. 43. 42. 23. N.