SUBMARINE DEPOSITS. 293 



the Bermudas, and extending to the north as far as latitude 38°. 

 Commencing at about longitude 50'' W., it follows southward 

 and westward toward South America nearly the line between 

 two and three thousand fathoms. It has been found close to 

 Porto Rico in deep water, and covers the floor of the ocean be- 

 tween it and the Bermudas. The western boundary of the 

 red-clay basin is not yet clearly defined. A narrow strip of this 

 basin reaches southward towards the ridge which separates it 

 from the northern extremity of the red-clay basin of the west- 

 ern South Atlantic. The smaller red-clay basin of the eastern 

 Atlantic lies between the Cape Verde Islands and the Dolphin 

 Rise. The eastern red-clay basin of the South Atlantic, sepa- 

 rated by the Challenger Ridge from the western red-clay basin, 

 is situated to the westward of equatorial Africa. The western 

 red-clay basin of the South Atlantic probably stretches into the 

 Southern Ocean. 



