40 THE CORAL REEFS OF THE MALDIVES. 



However, when we speculate upon the origin of the larger faros of some 

 of the northern groups, as Ari, North Male, Malosmadulu, and Tiladuramati 

 (Pis. 2, 3, 4), the conditions now existing do not warrant the conclusion 

 that they have been formed by the junction or coalescence of adjoining 

 faros. The great size and depth of the lagoons of some of the faros, the 

 depth of the passages separating them, their great width, — all the.se factors 

 indicate that the faros have grown from depths of eighteen to twenty 

 fathoms on secondary elevations of the greater plateau, with much the same 

 shape they now have. In their upward growth they have been modified 

 so as to become faros differing in the width of their rims, their outline, 

 the depth of the lagoons, the number of banks and islets or islands thrown 

 up on the rim flats ; or the lagoons may even have been completely filled, and 

 the faro changed to a great reef flat or even an island steep to with a 

 fringing reef, where all trace of the original faro has been lost. Of course 

 we do not deny that faros may join in time if they were originally separated 

 by comparatively shallow passes. This we see taking place by the growth 

 of corals in cusp-like spits from the slope of a rim flat, which enclose 

 shallow parts of the adjoining waters — a process somewhat similar to that 

 by which adjoining islands on wide reef flats become connected into a larger 

 island from the throwing out of sand-spits or of shingle-spits, either on the 

 lagoon or the sea face of the outer rim of an atoll, forming great bays which 

 become eventually filled ; a process which takes its greatest development, 

 perhaps, in the Ellice, Gilbert, Marshall Islands, and also occurs in other 

 groups of atolls in the Pacific. 



An examination of the charts (Pis. 2-6) shows a few instances where 

 adjoining faros in the interior of Ari, North Male, and the groups just men- 

 tioned may have coalesced. The distance separating the rings which crop up 

 within the enclosed area of Male and Ari furnishes no evidence that they 

 have been formed by the coalescence of adjoining faros. The irregularly 

 shaped banks and faros are additional evidence of their having grown up on 

 secondary inequalities of the plateaus of these groups. 



The western rim of one of the rings on the northwest face is circular ; the 

 other is digitate with deep indentations cutting into the wide irregular 

 eastern flat (PI. 4). 



