VOLCANO ISLANDS  , three small islands in the western Pacific Ocean, S. of the Bonin Islands, forming part of the Japanese empire (annexed in 1891) . They are also known as the Magellan Archipelago, and in Japan as Kwazan-retto (series of volcanic islands) . They are situated between 24° and 26° N. and 141° and 142° E . Their names are Kita-iwojima (Santo Alessandro), Iwo-jima (Sulphur) and Minamiiwo-jima (Santo Agostino) . Kita-iwo-jima--which, as its name (kita) implies, is the most northerly of the three—rises 2520 ft. above the water, and Minami-iwo-jima, the most southerly, to a height of 3021 11 . The islands are not inhabited . With this group is sometimes included another island, Arzobispo, nearer the Bonin group .