SOUTH MALOSMADULU. 59 



fifty-eight fathoms. This small faro, for it would be considered small 

 even if it formed a part of one of larger groups, differs in no way from 

 a large number of the characteristic faros of the Maldives. But Karidu 

 has all the characters of a small Pacific atoll ; it is isolated, separated 

 by wide channels from the nearest groups, and instead of rising, as do 

 other Maldivian faros, from a broad bank with an average depth of from 

 twenty to thirty-five fathoms, it rises as the summit of a diminutive mound, 

 surrounded by depths of nearly three hundred fathoms. Side by side iden- 

 tical structures exist which have been built up in one case from the mini- 

 mum depths of twenty to thirty-five fathoms ; and in the other, upon 

 summits rising from depths of over three hundred fathoms ; and certainly 

 the former do not owe their origin to subsidence. Otherwise Karidu has 

 been formed by the subsidence of a plateau to a depth of nearly 300 

 fathoms, Gaha Faro to 100, Makunudu to nearly 800, Ihavandiffulu to 

 250, Middle Malosmadula to 100 or 150, Rasdu to 120, Wataru to 200, 

 the hosts of small atolls on the outer faces of the Maldivian groups and of 

 the rings and faros within these groups to twenty or thirty-five fathoms 

 (PI. 1). The different depths to which these atolls have sunk all occur 

 within the same district, and postulate an iri'egularity in the rate of sub- 

 sidence of different and adjoining tracts of this area which it is diflficult to 

 imagine, and for which a very slow and regular rate of subsidence has 

 always been demanded. We can far more readily understand the existing 

 conditions as due to the diSerent levels to which the irregular bottom of 

 the great Maldivian plateau has been elevated. In fact, the topography 

 of this wide submarine ridge is neither mox'e nor less varied than that of 

 a mountain plateau. 



South Malosmadulu. 



Plates 1, 3; 8 b, fig. 10 ; 8 c, fig. 28 ; 22-28 ; 29, fig. 2. 



South Malosmadulu (PI. 3) is irregularly triangular, its apex facing east; 

 the greater part of the enclosed basin of the group, in a belt parallel to the 

 south face is filled with large faros, many of them more than three miles 



