BY W. G. WOOLNOUGH. 487 



New Zealand may almost be regarded as a continental area by 

 itself, since, according to Hutton,* "sedimentary rocks are repre- 

 sented of nearly all ages, from Archaean upwards, and all but the 

 lowest have yielded fossils, in some places abundantly. 

 Metamorphic and eruptive rocks of nearly all kinds." 



If we compare the region under consideration with others in 

 the world, we meet with certain marked points of similarity, but 

 at the same time the south-western area of the Pacific is unique 

 in many of its characteristics. 



One of the areas which may be mentioned for comparison is 

 the gap between North and South America, with its included 

 islands. Of the West Indian Islands practically all the larger 

 ones contain continental rocks. In the Lesser Antilles, according 

 to Spencer,! no ancient rocks come to the surface. Trinidad is 

 different, its relationships being distinctly continental. The 

 channel which separates it from the mainland of South America 

 is only 36 feet deep. Continental rocks appear in the island. 

 They are represented by crystalline schists, sandstones, shales, 

 ■&C., along the northern side of the island. The shallow submarine 

 plateau, upon which Trinidad stands, runs northwards towards the 

 jchain of the Lesser Antilles, and round by Avay of the Greater 

 Antilles to the middle part of the Central American Isthmus 

 and also to Florida. It forms an almost continuous ridge crossed 

 in places by deep furrows, but nowhere as much as 1000 fathoms 

 in depth. Enclosed by this submarine plateau are three large 

 areas of deeper water, the largest of which is the Carribbean Sea, 

 with depths ranging over 2000 fathoms. 



In the case of Madagascar we have another very interesting 

 comparison. The island forms an undoubted outlier of the 

 African Continent. According to Sr.esst it is built up of a core 



* Q.J.G.S. xli. (1885), p. 191. 

 t "On the Geological and Physical Development of Dominica," &c. 

 ■Q.J.G.S. Iviii. (1902), p. 841. And "On the Geological and Physical 

 Development of Barbadoes," &c. Ibid. p. .345, 



:;: " Das Antlitz der Erde." Vol. i. p. 53J, et seq. 



