RAIATEA AND TAHAA. 159 



Motu Araara off the southern extremity of Huaheine is the only island 

 on the outer edge of the barrier reef wliich has i-emained to indicate the 

 distance to which the volcanic slopes on the southeastern face of the island 

 at one time extended (PI. 210, fig. 1). 



Raiatea and Tahaa. 



Plates 93; 94, figs. 1-3 ; 96, fig. 3; 210, fig. £ 



We followed the east coast of Raiatea from Teavarua Pass round to Paipa'i 

 Pass on the west coast of Tahaa. There are a number of volcanic islands on 

 the outer reef of Raiatea and Tahaa, indicating the extent of the submarine 

 platform of erosion which surrounds these islands. This platform varies in 

 width from three quarters of a mile to nearly two miles (PI. 210, fig. 2). 

 The lagoon is in many places over a mile wide, with deep indentations or 

 harbors, reaching into the valleys formed by the spurs running east and 

 west from the main ridge of Raiatea. Some of these harbors are nearly 

 three miles in depth, cutting well inland towards the centre of Tahaa and 

 Raiatea (PI. 210, fig. 2), as Hamene, Teoneroa haaoa, and Pari Bays in 

 Tahaa. Faaroa Bay reaches more than one third across the width of 

 Raiatea, and a number of indentations extend far up into the broad valleys 

 which stretch from its central ridge towards the east and west shores of 

 the southern part of Raiatea. 



The northern reef fiat of Tahaa is studded with numerous islands and 

 islets (Pis. 93, fig. 2 ; 96, fig. 2 ; 194, figs. 1-3), running at right angles to 

 the outer edge of the barrier reef flats (PI. 210, fig. 2), much as we have 

 seen the great sand islands and islets thrown up on the outer faces of the 

 Paumotus and of the Marshall Islands. This indicates that during the 

 prevalence of northeasterly and northwesterly winds on these shores a large 

 mass of dead material is derived from the outer edge of the northern face 

 of the reef flat, and goes to build up the islands bordering the outer edge 

 of the barrier reef. The islands are from one to one and a half miles 

 distant from the shore, and are a very characteristic feature of the northern 

 extremity of Tahaa (Pis. 94, figs. 1-3 ; 96, fig. 2). Nowhere in the Society 



