12 FUNAFUTI ATOLL. 



eroded the loose coral blocks with the breccia sheet that lay 

 behind it, until the storm had made a breach half across the islet. 

 Afterwards the waves in the usual course of their work rebuilt 

 the shingle bank as it now stands. Before the re-erection of 

 the latter, drifting seeds of mangrove reached the swamp and 

 originated the present thicket. 



The shingle embankment referred to continues along the whole 

 windward face of the atoll, being highest at the eastern angle 

 and diminishing north and south where the trade winds strike 

 the beach obliquely. On the leeward side it is entirely absent. 

 Six feet above the usual level of the ocean waves it represents 

 the greatest altitude, the culminating peak, of the atoll. Great 

 blocks of coral packed high and toppled over by gales of past 

 years, all weathered and discoloured, compose the inland face of 

 the bank, their appearance recalling a heap of blackened lava and 

 scoriae from some volcanic hill side. A similar scene reminded 

 Dana of " a vast field of ruins. Angular masses of coral rock, 

 varying in dimensions from one to a hundred cubic feet, lie piled 

 together in the utmost confusion ; and they are so blackened by 

 exposure, or from incrusting lichens, as to resemble the clinkers 

 of Mauna Loa ; moreover, they ring like metal under the hammer. 

 Such regions may be traversed by leaping from block to block, 

 with the risk of falling into the many recesses among the huge 

 masses. On breaking an edge from the black masses, the usual 

 white colour of coral is at once apparent."* On the seaward 

 face the blocks of coral are smoothed, rounded, and beach worn, 

 till all semblance of their Actinozoan origin has been ground 

 away. 



On examining the beach at low water, the shingle bank was seen 

 to be underlaid throughout, like that of the north arm of the swamp, 

 by a breccia of angular coral fragments, in size usually of a man's 

 head or fist. The corals appeared to belong to the same species 

 as those now thrown up on the beach, some of which, presumably 

 deep water species, only occurred too ground and battered to be 

 worth collecting. A species, apparently a large Mussa, I knew 

 well by sight, but was never fortunate enough to find in even toler- 

 able preservation. Here and there this breccia was carved by 

 the waves into fantastic turrets and pinnacles or extended sea- 

 ward in shelves. The highest point it reached was a little above 

 high tide mark. I thought sometimes that the mode of weather- 

 ing and the composition of the rock indicated an upper and a 

 lower bed, but of this I could not satisfy myself. The history of 

 this stratum appears to be that fragments of coral torn from the 

 growing edge have been packed in a bank like that now facing 

 the surf, that sea or rain water cemented these into a sheet of 

 breccia, and that a shift of winds set the waves to tear down what 



* Loc. cit., p. 178. 



