MOTu rri. 165 



reef flat. On the northeastern and on the northwestern extremity of the 

 reef flat two long, low wooded islets, with two islets in the gap separating 

 them, occupy the outer edge of the reef (Pis. 104, fig. 4 ; 105, fig. 1 ; 210, 

 fig. 4), similar in all respects in structure to that of the islands which 

 characterize the east and northwest shore of Bora Bora. On the east face 

 of the barrier reef flat south of Tuanae Island numerous outliers of volcanic 

 rocks are scattered (PI. 105, fig. 2), indicating the position and structure of 

 the foundation upon which corals have grown. Similar outliers occur in 

 great number on the southern and western barrier reef flats. The main 

 peak of Maupiti is a remarkable perpendicular rocky bluff resembling tlie 

 ruins of a gigantic castle (Pis. 104, fig. 3 ; 105). Maupiti resembles in 

 ever}' respect Bora Bora, though its barrier reef fiat has a proportionately 

 greater development. 



Motu Iti. 



Plates 104, fifjs. 1, 3 ; 20fi. 

 Motu Iti ^ consists of two low islands : one of these is L-shaped and consti- 

 tutes the land rim of the northern part of the northwestern and eastern 

 faces and of a wide reef flat; the other is V-shaped, forming the land rim 

 of the southwestern part of the reef flat (Pis. 104, figs. 1, 2; 202). These 

 two islands are similar to those of Tetiaroa. They have been thrown up on 

 the wide triangular barrier reef flat, nearly eight miles in length and four 

 miles at the base. The V-shaped island forms the south flank of the lagoon, 

 into which there are two narrow and shallow passes. The lagoon appears 

 to be shallow (PI. 104, fig. 1). Of course the nature of the foundation base 

 of this atoll is problematical. .Judging by the character of the other islands 

 in the vicinity, the underlying rocks of the reef flats are probably vol- 

 canic. They represent a stage of denudation somewhat more advanced 

 than that of Maupiti, as if the whole central ma.ss of that peak had been 

 denuded to the level of the sea. At Motu Iti I could not see any volcanic 

 outliers, such as are so common at Maupiti, Bora Bora, and on the barrier 

 reef flats of other islands of the Leeward Society Islands. 



1 A. Chart lOCO. 



