Organ Mountains, [162].

Orgoñez, Rodrigo de, [81].

Oriente River system, [353].

Orinoco River, [401], [403];

delta of the, [415]-[416];

entrance upon, from the sea, [416]-[417].

Oroya Railroad, [330]-[331].

Orton, James, quoted, [354], [369].

Ossorio, General, [124]-[125].

Pacific Ocean, Balboa’s discovery of, [22]-[25];