SUVADIVA. 135 



Along the southern part of the western rim of Suvadiva we find three 

 narrow reef flats, separated by deep passes, flanked on the western face by 

 numerous islands, while on the eastern faces are a number of small lagoons 

 or bays or extensive narrows with from three to ten fathoms in depth, 

 formed by the growth of coral patches or stretches off the eastern face 

 of the western reef flats. These patches, becoming connected, enclose a 

 part of the littoral area of the lagoon, shutting it off more or less from 

 the greater lagoon. 1 



Notwithstanding the general resemblance of Suvadiva to some of the 

 large atolls of the Marshall Islands, where corals do not flourish in the 

 interior of the lagoons, yet the corals on the slopes of the interior banks 

 and on the inner slopes of the outer reef flats of Suvadiva are more flourish- 

 ing than either in Kolumadulu or Haddummati. From the great area of 

 the deep passes opening into Suvadiva, as compared to that of Kolumadulu 

 and of Haddummati, we can readily see how the inner waters of the group 

 retain a far more oceanic character than the enclosed areas of Haddummati 

 and of Kolumadulu. A glance at the chart (Pis. 5, 6) will bring out the 

 marked contrast existing in that respect between these groups. 



Within the lagoon many islands and a great number of small banks are 

 scattered over the plateau of Suvadiva. It should be remembered in com- 

 paring the Maldive atolls and those of the Pacific that the character of 

 the islands in the lagoons is very different from that of the islands within 

 the groups of the Maldives. In the former they are few in number and 

 generally the remnants of the extensive denudation of somewhat more ex- 

 tended land areas, consisting of older limestone rocks, while in the Maldives 

 the islands are the result of the active growth of corals now going on. 



On the sea face of Mafuri (PI. 73) horses of conglomerate run across 

 the base of the beach and the reef flat; the position of these horses indicates 



1 When discussing the origin of the Maldives, Darwin * states that small reefs within large lagoons 

 or broad lagoon channels would grow up during subsidence, and therefore would sometimes be found 

 rising abruptly from a greater depth than that at which the efficient polypifers can flourish. This 

 Darwin considers to be well exemplified in the small abruptly sided reefs with which the deep lagoons 

 of the southern Maldive atolls are studded. He considers that the rings in the margin of the northern 

 Maldive atolls, although broader than the exterior of an ordinary atoll are only modified portions of 

 such a reef, and that the central rings occupy the same relative position as the knolls occurring in 

 lagoons. 



* Lor. cit , p. 141. 



