408 



J. STANLEY GARDINER. 



soundings between Guradu and Buruni in Kolumadulu, nor in isolated ones from north to 

 south in Haddumati. The vast majority of the shoals that we fixed were found to be as 

 marked in the chart. Mr Cooper, however, observed that several, which were represented as 

 reaching the surface, only existed as mounds well below the low tide level. In passing through 

 Kolumadulu, too, I observed that a few presented in the sunlight a dark, blackish appear- 

 ance — a contrast to the vivid brightness of a growing reef Two of these near the north 

 of the line between Guradu and Buruni I crossed, finding both completely submerged and 

 apparently quite dead, being covered by fine mud with no living corals. 



Scale 

 1 I 2 i 1^ s Miles 



K'""" 



Fig. 107. Haddumati Atoll {slightly altered from the Admiralty Chart). 



As far as the passages were concerned, I only examined four, and found changes in all. 

 This was remai'kable and probably due to the fact that all four were among the largest in 

 either atoll. In Kolumadulu the Buruni reef had grown out somewhat to the north-east, 

 its south-east horn seeming in addition to have been somewhat cut away, and the Guradu 

 passage had nan-owed near its seaward end by reefs growing out into it from either side. 

 In Haddumati the Munafuri passage has as least depth in its centre 4 fathoms (seven sound- 

 ings), but it differs from the Guradu one in having very distinct outgrowing horns towards 

 its lagoon end. The Gadu channel is constricted by an outgrowth of the Gadu reef to the 

 west, and by that to the south of both the reefs between Gadu and Mamendu, the Hitadu 

 reef showing no changes. 



