AGE of individual corals. Aiou. Aitutaki. Aldabra. Alert reef. Alexander, Grand Duke, island. ALLAN, Dr., on Holuthuriæ feeding on corals. On quick growth of corals at Madagascar. On reefs affected by currents. Alloufatou. Alphonse. Amargoura. (Amargura.) Amboina. America, west coast. Amirantes. Anachorites. Anambas. ANAMOUKA, description of. Anamouka. Anadaman islands. Antilles. Appoo reef. Arabia Felix. AREAS, great extent of, interspersed with low islands. Of subsidence and of elevation. Of subsidence appear to be elongated. Of subsidence alternating with areas of elevation. Arru group. Arzobispo. ASCIDIA, depth at which found. Assomption. Astova. Atlantic islands. ATOLLS, breaches in their reefs. Dimensions of. Dimensions of groups of. Not based on craters or on banks of sediment, or of rock. Of irregular forms. Steepness of their flanks. Width of their reef and islets. Their lowness. Lagoons. General range. With part of their reef submerged, and theory of. Augustine, St. AURORA island, an upraised atoll. Aurora. AUSTRAL islands, recently elevated. Austral islands. Australia, N.W. coast. AUSTRALIAN barrier-reef. Australian barrier. Babuyan group. Bahama banks. Balahac. Bally. Baring. BARRIER-REEF of Australia. Of New Caledonia. BARRIER-REEFS, breaches through. Not based on worn down margin of rock. On banks of sediment. On submarine craters. Steepness of their flanks. Their probable vertical thickness. Theory of their formation. Bampton shoal. Banks islands. Banks in the West Indies. Bashee islands. Bass island. Batoa. Beaupre reef. BEECHEY, Captain, obligations of the author to. On submerged reefs. Account of Matilda island. BELCHER, Captain, on boring through coral-reef. Belize reef, off. Bellinghausen. Bermuda islands. Beveridge reef. Bligh. BOLABOLA, view of. Bombay shoal. Bonin Bay. Bonin group. BORINGS through coral-reefs. BORNEO, W. coast, recently elevated. Borneo, E. coast. S.W. and W. coast N. coast. Western bank. Boscawen. Boston. Bouka. Bourbon. Bourou. Bouton. BRAZIL, fringing-reefs on coast of. BREACHES through barrier-reefs. Brook. Bunker. Bunoa. BYRON. Cagayanes. Candelaria. Cargados Carajos. Caroline archipelago. Caroline island. Carteret shoal. CARYOPHYLLIA, depth at which it lives. Cavilli. Cayman island. Celebes. Ceram. CEYLON, recently elevated. Ceylon. CHAGOS Great Bank, description and theory of. CHAGOS group. Chagos group. CHAMA-SHELLS embedded in coral-rock. CHAMISSO, on corals preferring the surf. CHANGES in the state of Keeling atoll. Of atolls. CHANNELS leading into the lagoons of atolls. Into the Maldiva atolls. Through barrier-reefs. Chase. China sea. CHRISTMAS atoll. Christmas atoll. Christmas island (Indian Ocean). Clarence. Clipperton rock. COCOS, or Keeling atoll. Cocos (or Keeling). Cocos island (Pacific). COCHIN China, encroachments of the sea on the coast. Cochin China. Coetivi. Comoro group.