300 



ISLAND LIFE. 



[part II. 



areas of less depth, varying from two hundred to a thousand 

 fathoms, and which may therefore indicate the sites of submerged 

 islands of considerable extent. When we consider that east 

 of New Zealand and New Caledonia, all the larger and loftier 

 islands are of volcanic origin, with no trace of any ancient strati- 



[60 E. r?o ISO no tBO t50 \ex) iso tao mw. 



MAP OF THE NORTH PACIFIC WITH ITS SUBMERGED BANKS. 



The light tint shows where the sea is less than 1,000 fathoms deep. 

 The dark tint „ ,, more than 1,000 fathoms deep. 



The figures show the depths in fathoms. 



fled rocks (except, perhaps, in the Marquesas, where, according 

 to Jules Marcou, granite and gneiss are said to occur) it seems 

 probable that the innumerable cortil-reefs and atolls, which occur 

 in groups on deeply submerged banks, mark the sites of bygone 

 volcanic islands, similar to those which now exists but which, after 



