REVILLAGIGEDO  , an isolated, uninhabited

group of rocky islands in the N . Pacific, lat . 8° N., long . 112° W., belonging to Mexico, and forming part of the state of Colima.' They are about 420 M. from the Mexican coast and comprise the large island of Socorro (San Tomas), 24 M. long by an average of 9 M. wide, and the three widely'separated islets of San Betiedicto, Roca Partida and Clarion, with a total area of 320 sq. m . The island of Socorro has an extinct volcano 366o ft. high . The islands have certain remarkable zoological features, comprising several birds and reptiles allied to those of the Mexican main-land but differing from them in species . The archipelago derives its name from the Spanish viceroy who governed Mexico from 1746 to 1755 .