24 THE CORAL REEFS OF THE MALDIVES. 



distance is fully seventy miles, and its greatest depth ten hundred and 

 fifty-seven fathoms. Still further north, the Laccadive group, small iso- 

 lated summits, with comparatively small atolls, resemble in every respect 

 the smaller and widely separated atolls of the Ellice and Gilbert groups, — 

 a series of independent summits separated by at least two thousand fathoms 

 of water and scattered over a distance of fifteen degrees of latitude. The 

 distance from Minikoi to the most distant Laccadive bank is not more than 

 four hundred and twenty miles, with depths of little over one thousand 

 fathoms. 



Line from Haddummati to Suvadiva (the One and half degree Channel) 

 (PI. 8 c, fig. 22). 



Our starting-point was halfway across the normal between the reef flats 

 off Gadu and Hitadu ; four miles south we obtained nine hundred and 

 eighty-seven fathoms (No. 24), with a bottom composed of fine coral sand, 

 broken shells, and Globigerinae. Fourteen miles south of Haddummati, 

 in ten hundred and seventy-eight fathoms (No. 25), we brought up small, 

 flat, irregularly shaped manganese nodules, from the size of coarse sand 

 to half an inch in length. 1 Twenty-nine miles south of Haddummati, about 

 in the centre of the channel, we sounded in eleven hundred and thirty 

 fathoms (No. 26), and brought up a mass of large light-green Globigerinae, 

 so abundant that they might be called Globigerina sand. Forty-four miles 

 south of the starting-point we obtained ten hundred and eighty-six fathoms 

 (No. 27), with the same Globigerina sand bottom as in the previous sound- 

 ing ; and two and three-quarters miles from the northern point of Suvadiva 2 

 we found eight hundred and ninety-nine fathoms (No. 28), with a coarse 

 greenish coral sand bottom, mixed with 'fragments of broken shells and 

 corals. The channel between Haddummati and Suvadiva is a very level 

 plateau of an average depth of somewhat over a thousand fathoms. The 



1 It is interesting to find this typical deep-sea oceanic deposit at such moderate depths, and 

 surrounded, as far as we know, by Globigerinae or Pteropod deposits. Further south, near Addu, 

 we also found manganese coating fragments of coral at very moderate depths (three hundred and 

 seventy-six fathoms). North, in the Fulidu Channel, fragments of coral coated with manganese were 

 obtained in three hundred and seventy-four fathoms. The coated fragments were much in the con- 

 dition of similar fragments dredged in the Straits of Florida at abont the same depth. 



2 A small nameless faro north of Matu Island. 



