THE SOCIETi' ISLANDS. 135 



THE SOCIETY ISLANDS. 



Plates S4-IO0, 201, 202, 208-210. 



We examined the eastern coast of Tahiti, and the western coast from 

 Papiete as far as Port Phaeton, at Taravoa Isthmus. We examined, in a 

 general way, the Leeward Society Islands : Murea, Huaheine, Raiatea, 

 Tahaa, Bora Bora, Motu Iti, and Maupiti. There are excellent charts of the 

 Society Islands,^ so that it was comparatively simple to study the typical 

 points of the group and to gain an idea of their structure as far as it relates 

 to coral reefs. The different islands present only modifications of one and 

 the same structure, so that the more careful examination which we made 

 of Tahiti and of Bora Bora undoubtedly gave us the key to the structure of 

 those islands we examined only in a more cursory way. We saw enough 

 of all of them to satisfy ourselves that tliere were no points of special 

 interest which were not well represented on the islands which we examined. 



The description we have given of the modifications of the fringing and 

 barrier reefs of Tahiti applies to all the other islands of tlie Society group ; 

 it varies only according to the shape of the island, the manner in which the 

 mountain ridges have been denuded, and according to its exposure to the 

 prevailing winds. The Society Islands are all volcanic, edged with shore 

 platforms, some of great width, upon which the barrier or the fringing reefs 

 of the islands have grown. The structure of the reefs of the Society 

 Islands is very similar to that of the reefs round the volcanic islands of Fiji. 

 A comparison, for instance, of the charts of Kandavu, Viti Levu, Mbengha, 

 Nairai, and of other volcanic islands of Fiji, with those of the Society 

 group, will at once show the identity of their structure. Huge platforms 

 of submarine denudation and erosion characterize both, with fringing and 

 barrier reefs determined by local conditions ; perhaps it is easier to follow 

 the clianges which have taken place in the Society Islands. Such islands 

 as Tahaa and Bora Bora, where we anchored, *as well as Maupiti, are admir- 

 able examples and epitomes of the structure and mode of formation of the 

 coral reefs of that group. 



1 A. Charts 1060, 1248, 1382, and other charts of details. 



