ANTICOSTI, a barren island of British North America, situated in the Gulf of St Lawrence, between lat. 49 and 50 N., and between long. 61 40 and 64 30 W., with a length of 135 miles, and a maximum breadth of 40. Most of the coast is dangerous, but lighthouses have been built at different points, and there are also provision posts for shipwrecked sailors. The lighthouse keepers and other officials are the only inhabitants of the island.