a small island in a bay of the same name, situated on the western coast of Africa, near the southern termination of the Great Desert. Major Rennell supposes it to be the island to which the ancients, and particularly Hanno, gave the name of Cerne. The Portuguese early formed a settlement there, and even made it for some time the principal point from which they attempted to penetrate into the interior; but the extensive deserts by which it was bordered were very unfavourable for this object, and the banks of the Senegal have been found more advantageous in every respect. The shores round Arguin, however, abound with valuable turtle, and the sea affords a considerable supply of stock fish. Long. 16° 20'. W. Lat. 20° 23'. N.