ANALYSIS OF THE SOUNDINGS TAKEN BY THE "AMRA." 19 



fathoms (No. 44), with a bottom of fine greenish coral sand with many 

 Pteropod shells and masses of Globigerinae. Eight miles from our starting- 

 point, we obtained twelve hundred and thirty-eight fathoms (No. 45), with 

 a bottom of fine grayish ooze containing mineral particles and many 

 Globigerinae. Twelve miles east of South Male, in continuation of the same 

 line, the depth has only increased to twelve hundred and seventy fathoms 

 (No. 46), with a bottom of fine gray Globigerinae ooze. We also sounded 

 one mile normal to the northeast horn of South Male, and obtained a depth 

 of three hundred and nineteen fathoms (No. 47), hard bottom. The only 

 other soundings off the east slope of the Maldive plateau are those off the 

 northern horn of Tiladummati and off Ihavandiffulu in Admiralty Chart, 66a, 

 and the soundings taken by the " Amra " on the way to Colombo from 

 Ihavandiffulu (Nos. 77-79). 



We ran two lines of soundings across the southern part of the central 

 basin of the Maldives, the one partly to the north, the other to the south 

 of the lines run across this basin by Mr. Gardiner. 1 His soundings of the 

 central basin agree well with those of the " Amra." 2 



Northern line of soundings from Waregili (west face of South Male) to 

 the east face of Ari (Kadibudu) (PI. 8 6, fig. 12). 



Across the basin separating the eastern from the western chain of groups 

 we obtained, two miles off the west face of South Male, a depth of one 

 hundred and eighty fathoms (No. 4) with fine greenish coral sand, many 

 Globigerinae, and a few Pteropods. Eight miles further west we found 

 the same bottom in a depth of two hundred and eight fathoms (No. 5). 

 Sixteen miles further, a point at about the same distance east of Ari, 

 the depth was two hundred and seventeen fathoms (No. 6), and three 

 miles off the east face of Ari it had diminished to one hundred and 

 seventy-seven fathoms (No. 7). 



These soundings' show a very flat basin dropping rapidly on both 'sides, 

 within a short distance of the edges of the channel, to nearly the depth of 

 the central part of the channel, with a bottom of an oceanic character: 

 Globigerinae mixed with Pteropods. 



1 Loc. cit., p. 4, fig. 2. * Loc. cit., p. 152, PI X 



