AMERICA ISLANDS  , a name given to Christmas, Fanning, Palmyra and attendant islets, belonging to Great Britain, in the Central Pacific Ocean, between the equator and 6° N., and about 160° W . They are so named because frequented for their guano by traders from the United States . Christmas Island is probably the largest atoll in the Pacific (it is about 90 m. in circuit), and was discovered by Captain Cook in 1777 . The islands were annexed by Great Britain in 1888 in view of the laying of the Pacific cable, of which Fanning Island is a station . Guano and mother-of-pearl shells are the principal articles of export; the population of the islands is about 300 .