Note 3 — Chapter V · THEORY OF THE FORMATION OF THE DIFFERENT CLASSES OF CORAL-REEFS.

I find from Mr. Couthouy’s pamphlet (page 58) that Aurora Island is about two hundred feet in height; it consists of coral-rock, and seems to have been formed by the elevation of an atoll. It lies north-east of Tahiti, close without the line bounding the space coloured dark blue in the map appended to this volume. Honden Island, which is situated in the extreme north-west part of the Low Archipelago, according to measurements made on board the Beagle, whilst sailing by, is 114 feet from the summit of the trees to the water’s edge. This island appeared to resemble the other atolls of the group.