140 BULLETIN OF THE 
mountainous character. Indeed, it is at first sight difficult to find the 
analogues of these great anticlinal-like folds in the existing structures 
of the land. They can hardly be classed with any of our known table 
lands, for the reason that such elevations are in all cases more or less 
associated with definite mountain folding. The only similar structure 
which is known to me is that exhibited in the ‘“ Cincinnati anticlinal,” 
that well known ridge extending from near Columbus, Ohio, to Northern 
Alabama. ‘This elevation in length and breadth may be compared to 
that of Florida, though it never had more than one half the height of 
the Floridian peninsula. 
In endeavoring to account for the Florida ridge, we must bear in 
mind the processes of deposition which have evidently occurred in this 
region. The geological history of the sedimentation is about as follows. 
To the west of Florida, in the Gulf of Mexico, we have a region which 
from a remote time has been the seat of extensive accumulation of sedi- 
ments. The Mexican Gulf in a more or less perfectly definite form is 
one of the oldest topographic features of this continent. It is, as is 
easily seen, the remainder of the continental trough which from an 
early time has received a great share of detritus from the Appalachian 
and Cordilleran fields. It has therefore been a region tending to sub- 
sidence, through the well known influence of the weight produced by 
sedimentary deposits on the surface of the earth. This subsidence has 
naturally been attended by phenomena of counter-thrust elevation, the 
characters of which I think are found in the curious uplifts of Yuca- 
tan and Florida, which serve in part to bound this region of downward 
movement. Besides the sediment contributed to the region of the 
Mexican Gulf from the continental portions of North America, there has 
been a considerable increase of such deposits from the island of Cuba. 
This island, which probably came above the level of the sea in the 
Mesozoic period, has evidently furnished a very large share of waste to 
the neighboring sea-floors, as is shown by the extensive erosion indi- 
cated in its highlands. A considerable portion of this detritus has 
doubtless been accumulated in the region now occupied by the Straits 
of Florida, and by the deep water between the Bahama Islands and the 
greater land masses of Cuba and Hayti. I am disposed to consider the 
extensive recent elevation on which rest the coral islands of the Baha- 
mas as possibly due to the down-bearing of the crust caused by these 
sediments. 
The Caribbean Sea has likewise long been a seat of extensive sedimen- 
tation. A number of great rivers draining from old mountain districts 
