268 CORALS AND CORAL ISLANDS. 



a single mountain range : — for example, the sickle-shaped line 

 of islets north of Nanuku. Tari-tari and Makin (Gilbert 

 Group, see map, page 165), lie together as if belonging to 

 parts of one island. Menchicoff atoll, in the Caroline Archi- 

 pelago, consists of three long loops or lagoon islands, united 

 by their extremities, and further subsidence might reduce it to 

 three islands. 



■% 





so of a.i-1 inch' to a. nulc*- * ; ^ 



] m 







MENCHICOFF ATOLL. 



Darwin in his account of the Maldives (op. cit., p. 37), 

 points out indications of a breaking up of a large atoll into 

 several smaller. The land with many summits or ranges of 

 heights may at first have had its single enclosing reef; but as 

 it subsided, this reef, contracting upon itself, may have encircled 

 separately the several ranges of which the island consisted, 

 and thus several atoll reefs may have resulted in place of the 

 large one ; and, further, each peak may have finally become 

 the basis of a separate lagoon island, under a certain rate of 

 subsidence or variations in it, provided the outer reef were .so 

 broken as to admit the influence of waves and winds. Some 

 of the large atolls of the Maldives are properly atoll archipel- 

 agos. 



The sizes of atolls offer no objection to these views, as they 



