12 THE CORAL KEEFS OF THE MALDIVES. 



ANALYSIS OF THE SOUNDINGS TAKEN BY THE "AMRA." 



Plates 1-8 c. 



A sounding (No. 76) 1 taken in the centre of Gallandu Channel between 

 Tiladummati and Ihavandiffuln (PI. 8 a, fig. 3) gave a depth of two hundred 

 and fifty-one fathoms with a bottom of coarse coral sand. 



On the Admiralty Chart 2 are a number of soundings off IhavandifEulu, 

 running into ten hundred and seventy-five fathoms, at a distance of eleven 

 miles to the westward, normal to the trend of the west face (PI. 8 a, fig. 1). 

 The outer edge of the slope must be quite flat, as nine hundred and ninety- 

 two fathoms was obtained five miles from the face of the atoll. The sound- 

 ings within a distance of five miles off the northern, the northeastern, and 

 southeastern faces indicate a slope similar to that off the western face. The 

 sounding of seven hundred and eighty-one fathoms, seven miles to the east 

 of Kelai, even indicates a somewhat flatter slope (PI. 8 a, fig. 2), off the 

 northeast horn of Tiladummati. From this a tongue of deep water runs 

 westward towards the ridge connecting Tiladummati with Ihavandiffulu 

 (PI. 2). 



The other lines we sounded to ascertain the slope of the oceanic faces of 

 the Maldives are off North Male (PI. 8 c, fig. 24), off the west face of North 

 Malosmadulu (PI. 8 c, fig. 26), off the west face of Ari (PI. 8 c, fig. 25), off 

 the east face of South Male (PI. 8 c, fig. 27), and off Addu (PI. 8 c, fig. 21), 

 in addition to the lines between the southern Maldives (PI. 8 c, figs. 22, 23). 



Line across the channel between Miladummadulu and the northern ex- 

 tremity of Makunudu (PI. 8 a, fig. 7). 



Makunudu is separated from Miladummadulu by a channel with an 

 oceanic bottom of a greatest depth of nearly eight hundred fathoms; it 

 rises from a small secondary plateau on the western slope of the northern 



1 The numbers refer to the List of Soundings, p. 2!). - Admiralty Chart, 06 a. 



