MUSEUM OF COMPARATIVE ZOOLOGY. 285 
answer. We have recorded evidence that similar terrace phenomena 
occur in Nicaragua, Yucatan, Jamaica, and San Domingo, and the coasts 
of South America have participated in these regional uplifts of Pleisto- 
cene and recent time, to which the slight elevation of the Gulf coast of 
the United States is insignificant. 
In these studies I have found no evidence that Cuba, since its earliest 
history (the Mesozoic) has had land connection with the United States. 
Unless there was some profound subsidence in Post-Tertiary time, such 
as I have been unable to detect, no possible deduction can make such a 
connection. In fact, I know of no positive evidence that it has been 
connected with our continent at all, and have only hypothetical evidence 
that the Pre-Tertiary land may have once extended toward the Yucatan 
peninsula, and that it was only then, if ever, that the Antillean and 
Cordilleran islands were united. Neither can we avoid conceiving that 
the subsequent elevations have brought the isthmian region up with it, 
making the present land connection between the continents. 
The axial direction of the general Antillean Post-Tertiary elevation is 
approximately east and west, and hence it is presumable that the sub- 
marine ridges were more likely to have been extended in that direction, 
and that to the north and south of this axis, which must theoretically 
be the remnant of a great east and west swell or fold, there must have 
existed corresponding sloping sides and synclinal troughs. It is but 
natural, then, that evidence of the continuation of the Cuban dias- 
trophism must be looked for in east and west lines rather than in lines 
_ north and south. 
We can also reasonably conclude that the orogenic development of 
Cuba, begun in some unknown period of antiquity, was practically com- 
pleted at the commencement of the Pleistocene, — that is, the develop- 
ment accompanied by displacement, folding, and vulcanism, — and that 
the stage of elevation then began, bringing up the old Pre-Pleistocene 
architecture and carving the mass into its terraces and present outlines. 
The group of regional elevations which I have described, although 
marking a wide interval of time, all occurred in a comparatively recent 
geologic period. To fix this time exactly would be impossible with the 
scant data at hand, but we can make some approximations. 
The oldest of the elevations, now represented by the Yunque level, 
certainly followed the period of folding which the Tertiary limestones 
underwent after their deposition. This folding, we may safely say, was 
Post-Tertiary, and took place in late Pliocene or early Pleistocene time, 
approximately, and marks the beginning of the re-emergence of modern 
