22 THE CORAL REEFS OF THE MALDIVES. 



characteristic of other channels separating the groups of the two sides of 

 the central basin of the Maldives. The bottom of this channel seems 

 to be composed wholly of coral sand and broken shells. 



A sounding of two hundred fathoms being marked in the Admiralty 

 Chart (66 b) in the centre of the channel between North and South 

 Xilandu, and indicating the same general depth found in other channels, 

 we did not think it necessary to make any other soundings while running 

 across to South Nilandu from Magudu. 



Mr. Gardiner sounded this channel and obtained a greatest depth of 

 two hundred and thirty-five fathoms in the centre of the channel. 1 



Line of soundings between Mulaku and Kolumadulu across the Kuda- 

 huvadu Channel from Mulaku to Wilifuri (PI. 8b, fig. 18). 



Four miles south of Mulaku we obtained four hundred and three fath- 

 oms (No. 17), with a hard rocky bottom. Nine miles from our starting- 

 point in the centre of the channel, we ran into six hundred and forty-nine 

 fathoms (No. 18), with a fine gray ooze. Two miles from Wilifuri, we 

 sounded in two hundred and eighty-two fathoms (No. 19), a depth consider- 

 ably greater than we found at the same distance off the west face of 

 Mulaku. 



The eastern opening of Kudahuvadu Channel is deeper than the corre- 

 sponding western channel separating South Nilandu from Kolumadulu. The 

 southern extremity of the central basin of the Maldive plateau dips rapidly 

 towards the east, judging from the soundings across Kudahuvadu (Nos. 17- 

 19, 36-38) and Veimandu (Nos. 20-23) channels. 



Line of soundings across Kudahuvadu Channel, between Kandufuri 

 (Kolumadulu) and Maimbudu (South Nilandu) (PI. 8 b, fig. 17). 



We obtained one and a half miles off Kandufuri two hundred and fifty- 

 three fathoms (No. 36), with a bottom of coarse coral sand mixed with 

 broken Pteropod shells. Halfway across the channel, six and a half miles 

 from our starting-point, we sounded in two hundred and fifty-one fathoms 



1 Loc. cit., p. 152, PI. X. 



