THE PAUMOTU PLATEAU. 27 



To the eastward of Makemo our soundings indicate (PI. 201 and Fig. 10) 

 a gradual increase in depth. Makemo and Neerou are separated by a 

 channel with a depth of 1221 fathoms. We find about the same depth 

 between Neerou and Tekokota, which with Hikueru seem to be on a shal- 

 lower ridge with not more than 1009 fathoms. Between Hikueru and 

 Marokau the depth increases to 1620 fixthoins; between the latter and 

 Hao it has increased to nearly 2200 fathoms. It is again over 2100 fathoms 

 between Hao and Aki-Aki, and over 2.300 fathoms between Aki-Aki and 

 Nukutavake. The latter, with Pinaki, are upon a distinct plateau with a 

 depth of less than 900 fathoms. So that we may state that east of Hao the 

 different atolls of the Paumotus rise independently, and are separated by 

 channels of considerable depths which are gradually becoming greater as 

 we go farther east (Pis. 201-203). 



From Pinaki to Nukutipipi (Fig. 11), crossing the deep channel wliich 

 runs parallel to the general trend of the Paumotus, we find a greatest 

 depth of 2467 fathoms, and reach the area of red clay again. 



Finally, on the line from Nukutipipi towards Mehetia (PI. 201 and 

 Fig. 12) we find steep slopes between the atolls, a depth of 1609 fathoms 

 separates Nukutipipi and Anu-Anurunga, 1890 fathoms is found between 

 the latter and Anu-Anuraro, and a stretch of red clay exists between it and 

 Hereheretue in 2524 fathoms. The area of the red clay extends towards 

 Mehetia, the deepest sounding towards that island being over 2400 fathoms. 



In the Paumotus the islands from Hao to Matahiva trend in a general 

 way from southeast to northwest. But the islands to the north of a line 

 from Rangiroa to Makemo, except Apataki, run at right angles to that line. 

 They are Takaroa, Takapoto, Manihi, Ahe, Raroia, Takume, Fakaina, and a 

 number of the outlying islands to the eastward, as Amanu, Tatakoto. The 

 islands of Nakutavake, Vahitahi, and Tatakoto run in a northeasterly direc- 

 tion, while others, like Reao, Puka-ruha, and' Marutea, run again from 

 southeast to northwest. 



There thus seem to be traceable a number of lines of uplieaval in the 

 group. Off Rangiroa, at right angles to its trend, run Ahe and Manila. A 

 second line at right angles to Apataki consists of Takapoto and Takaroa. 

 A third line off Makemo is formed by Raroia and Takume. While the out- 



