J. D. Dana—Oceanic Coral Island Subsidence. 85 
the main line of Cuba; and the latter course, the west-southwest, 
mm cross lines of islands in the Bahamas (one at the north ex- 
tremity, another in the line of Nassau, and others to the south- 
east), in the high lands of northwestern and southeastern Cuba, 
and in the Florida line of reefs, and even further, in a sub- 
merged ridge between Florida and Cuba. This combination of 
the two continental trends shows that the lands are one in sys- 
tem, if they were never one in continuous dry land. 
We cannot here infer that there was a reguiar increase of 
subsidence from Florida eastward, or that Florida and Cuba 
participated in it equally with the intermediate or adjoining 
seas ; for the facts in the Pacific have shown that the subsiding 
oceanic area had its nearly parallel bands of greater and less 
subsidence, that areas of greatest sinking alternated with others 
of less, as explained on page 828; and that the groups of high 
islands are along the bands of least sinking. So in the Atlantic, 
the subsidence was probably much greater between Florida and 
uba than in the peninsula of Florida itself; and greater along 
the Caribbean Sea parallel with Cuba, as well as along the 
ei have taken place about it; for it is not natural for 
an | 
Wenty miles to the southwest-by-west from the Bermudas, 
there are two submerged banks, twenty to forty-seven fathoms 
under water, showing that the Bermudas are not completely 
alone, and demonstrating that they cover a summit in a range 
of heights; and it may have been a long range. 
. ,+D the Indian ocean, again, there is evidence that the coral- 
island subsidence was one that affected the oceanic area more 
than the adjoining borders of the continent, and most, the cen- 
tral parts of the ocean. For, in the first place, the Archipelago 
of the Maldives narrows and deepens to the southward. Fur- 
ther, the large Chagos Group, lying to the south of the Maldives, 
“8 remarked upon by Darwin, contains but very little dry lan 
M any of its extensive reefs, while some of them, including the 
Great Chagos Bank, are sunken atolls. Again, still other large 
reefs n ly , lie to the southwest of the Chagos Group; 
while Keeling’s is another outlying atoll southwest of southern 
Sumatra and far ont toward mid-ocean. 
