Note 30 — Chapter IV · ON THE DISTRIBUTION AND GROWTH OF CORAL-REEFS.

Since the preceding pages were printed off, I have received from Mr. Lyell a very interesting pamphlet, entitled “Remarks upon Coral Formations,” etc., by J. Couthouy, Boston, United States, 1842. There is a statement (page 6), on the authority of the Rev. J. Williams, corroborating the remarks made by Ehrenberg and Lyell (page 71 of this volume), on the antiquity of certain individual corals in the Red Sea and at Bermuda; namely, that at Upolu, one of the Navigator Islands, “particular clumps of coral are known to the fishermen by name, derived from either some particular configuration or tradition attached to them, and handed down from time immemorial.” With respect to the thickness of masses of coral-rock, it clearly appears, from the descriptions given by Mr. Couthouy (pages 34, 58) that Mangaia and Aurora Islands are upraised atolls, composed of coral rock: the level summit of the former is about three hundred feet, and that of Aurora Island is two hundred feet above the sea-level.