76 "ALBATEOSS" TROPICAL PACIFIC EXPEDITION. 



Pakarava. 



Plates 4.6-50; 51, fig. £ ; 5S,fig. 1; ^01, 203; SO4., figs. 1, 7. 



We spent some time in the lagoon of Fakarava. This atoll and Makemo, 

 Hao, and Rangiroa are the four largest atolls of the group, Rangiroa being 

 somewhat the larger. Fakarava is about thirty-two miles long, ten miles 

 wide, and rectangular in form. It runs from southeast to northwest; there 

 are two ship passages, one on the northern face and the other on the south- 

 ern face of the atoll. The northern passage and the northern part of Faka- 

 rava have been surveyed by the French,^ and the officers of the " Albatross " 

 made a running survey of the western face from Ngarue Pass to the south- 

 ernmost point of the atoll. On the lee side the atoll is fringed by large well- 

 wooded islands, while on the weather side there is a wide reef flat on which 

 small islands are found on the inner edge of the reef flat ; on the northern 

 face to the westward of Ngarue Pass a series of larger islands also forms the 

 land rim. What is very characteristic of this lagoon is the large area which 

 is studded with islands and islets, showing that probably a great part of the 

 atoll of Fakarava was once a wide flat,^ composed of corallif erous limestone, 

 which has little by little been denuded, dissolved, and cut down to the 

 existing level. With the prevailing southeasterly trades a considerable sea 

 runs on the lagoon side of the west coast of the atoll, which is raked 

 diagonally by the trades from one end of the lagoon to the other. The 

 same is the case with nearly all the larger lagoons which trend in a north- 

 westerly direction, like Hao, Makemo, and Rangiroa, as well as with lagoons 

 of somewhat less dimensions like Apataki, Arutua, Kaukura, and Tahanea, 

 as well as others of smaller dimensions, all of which are swept by the prevail- 

 ing trades. 



The, width of the western reef platform is not much greater than that of 

 the land rim on the lee side, showing plainly that the existing condi- 

 tions are such as to favor the piling up of material on the lee side, while it 

 is carried off on the weather side. It is evident, from the position of the 

 islands on the lee face of Fakarava, that whei-e the trend of the land rim is 



1 PI. 204, fig. 7. 



2 Probably similar to the great flats of the lagoons of Anaa and Tahanea. 



