162 "ALBATROSS" TROPICAL PACIFIC EXPEDITION. 



reef flat. To the north of Teveiroa, on the west coast, a number of 

 long narrow islands, running at I'ight angles to the outer line of the 

 barrier reef flat, indicate the manner in which the barrier reef flat has 

 little by little been covered by the material tlirown up during the preva- 

 lence of the westerly and northwesterly winds (Pis. 96, fig. 3 ; 97-99). 

 The gaps between the islands being gradually reduced by dams formed 

 either on the lee or the weather side (Pis. 96, fig. 8 ; 97, fig. 2 ; 99, fig. 

 3), exactly as we have described the formation of the land rim for many 

 of the atolls in the Pacific. 



Teveiroa consists of a series of smaller islands which have been 

 united, while the islands immediately north of it are still disconnected 

 (PI. 210, fig. 3). On the northeast and east coasts we find long islands 

 with here and there a gap indicating the manner in which the land 

 rim of those sides of Bora Bora has been thrown up, and has little by 

 little formed a continuous island on the northeast face, and a continuous 

 island on the southern part of the east face (PI. 98, fig. 1) : the long narrow 

 islands are separated by a cluster of small islands which are gradually ex- 

 tending lagoonward over the wide barrier reef flat. Parts of the longer 

 islands are here and there almost separated by indistinct gaps, as is seen on 

 the chart (PI. 210, fig. 3). On the south face of Bora Bora and on the west 

 face (PI. 97, fig. 3) the wide barrier reef flat, over a mile in width, is in part 

 bare or awash or covered with coral patches, separated by pools or lanes of 

 water varying in depth from eight to ten feet. The lagoon which separates 

 the main island of Bora Bora from the barrier reef flat forms on the eastern 

 face a series of basins nearly distinct, separated by the spurs which have run 

 out in points from the main ridge of the island ; some of these points have 

 been cut, leaving here and there small islets, like Pitu u Uta and Pitu u Tni, 

 outliers completely surrounded by the barrier reef flat, or narrow rocky 

 spurs like Pan Point, Tahio and Tahihi Points. Matira Point is formed by 

 a series of islets and of rocks running half-way across the wide southern 

 barrier reef flat, showing perhaps more plainly than at any other point 

 in Bora Bora the former extension of the slopes of the island, to the 

 outer edge of the barrier reef flat (PI. 210, fig. 3). 



The island of Pitu u Tai is the most distinct outlier of one of these vol- 



