AGASSIZ: BAHAMAS. 



175 



In the West Indies_, beginning with the Bermudas, is the mass upon 

 which the so called atoll has been formed, — an island rising out of a 



10° n' 





CLIPPERTON ISLAND. 



water. Best boat landing on the north side of the island. On the chart " Deep 

 water" is marked in the atoll to the westward of the trachytic rock near the south- 

 ern face of the island. " Great coral ridges alternating with deep water " is the 

 legend of the central part of the lagoon. A few insignificant islets are mapped in 

 the lagoon near its northwest face. The atoll is pear shaped, its axis running south- 

 east to northwest ; its greatest breadth is over one and a half miles, and its length 

 more than two. 



On Mr. Jensen's chart the island is represented as a narrow ring of coral rock 

 surrounding the lagoon. This dry belt is nowhere more than seven hundred feet 

 wide, except to the southwest of the trachytic rock, wiiere tliere is a short spit ex- 

 tending into the lagoon, the point of which is perhaps fifteen hundred feet from the 

 outer edge of the island. At several points the coral rock belt is not more than two 

 hundred feet wide, and along the greater part of the southwest coast it varies be- 

 tween four and five hundred feet in width. A similar narrow stretch of perhaps 

 three quarters of a mile extends along the north side. Tiiis connects the two 

 broadei shore tracts of the eastern and northwestern parts of the island. 



