MARIAS, LAS TRES, three islands in the North Pacific Ocean, lying off the W. coast of Mexico, and belonging to the state of Xalisco; between 21. and 22. N. Lat., and 106. and 106. 30. W. Long. They stretch in a line from N.W. to S.E.; and the largest of the three, which is the furthest to the N.W., is about 15 miles in length and 8 in breadth. The next island is about 24 miles in circumference, and the smallest, which lies to the S.E., has a circuit of 8 miles. These islands are barren and uninhabited, but they abound in wood, water, salt, and game, and were formerly often visited by English and American whaling vessels. They were visited by Diego de Mendoza in 1532, and named by him Islas de la Magdalena.