80 Transactions. 



In a short paper of this kind it will be impossible to attempt 

 anything more than a general discussion of these three matters. 



A reference to any map which shows the contours of the 

 western Pacific at once makes it clear that the northern peninsula 

 is not continued far as a submarine ridge below the waters 

 of the Pacific. Still, there are submarine ridges parallel to it. 

 A small ridge of this nature lies relatively close to the land, 

 but does not extend far to the north. Over a portion of 

 it the water is less than 500 fathoms in depth. A second 

 ridge, of much greater importance, lies five hundred miles to the 

 west. This, like the other, has a fairly large portion which 

 is less than 500 fathoms below the surface of the water. 

 The ridge continues as far north as New Caledonia without in 

 any place dipping below the 1,000-fathom level. 



There is, however, another submarine ridge of some import- 

 ance north of New Zealand. Commencing about three hundred 

 miles north of the Bay of Plenty, this ridge, less than 1,000 

 fathoms below the sea-level, extends continuously nearly as 

 far north as Samoa. In ordinary maps it is not indicated 

 as continuous, but as divided into two portions between the 

 Kermadecs and the Tonga Islands. There does not appear 

 to be any reason to divide the ridge into two parts in this manner. 

 It is true that those soundings that have been made between 

 these groups of islands indicate rather deeper water, but none 

 of the soundings are in the direct line of the ridge, and all 

 parts of it are extremely narrow. The evidence that is avail- 

 able seems to point to the continuous nature of the ridge rather 

 than to its separation into two parts. The ridge appears to be 

 a continuation of the trend-line of the main structural features 

 of New Zealand. Wherever the ridge rises to the surface it 

 -displays volcanic rocks, as at the Kermadecs and at Tongatabu, 

 though it must be remembered that Professor Thomas has 

 obtained specimens of syenite from the former group. To the 

 •east of this ridge there is a deep rift in the bed of the Pacific. 

 In places it is 5,000 fathoms in depth, and there appears 

 to be definite evidence that it is 4,000 fathoms and more 

 in depth throughout a distance as great as the length of the 

 ridge that borders it so closely on the west. The evidence in 

 favour of the continuity of the rift is similar to that given above 

 — viz., in those places where discontinuity is generally repre- 

 sented in maps no soundings have been made in the direct 

 line of the rift. 



So far as submarine contours go, it appears from the fore- 

 going statements that there is no definite evidence as to the 

 nature of the northern peninsula. Trend-lines there undoubtedly 

 are, and some of these are parallel to but not continuous with 



