MUSEUM OF COMPARATIVE ZOOLOGY. 283 
that no coastal accumulations are preserved around its perimeter. This 
elevation likewise developed the present outline of the island almost in 
its entirety, and perhaps in greater area, which has since been destroyed 
by erosion. 
5. Following this older and greater Post-Tertiary elevation, and inter- 
vening between it and the time of the Cuchilla, or five-hundred-foot 
level, there was a long period of erosion, cutting down the country to the 
Cuchilla plain, which was at that time marine base level. 
6. Renewed and general elevation of the island commenced in recent 
time, after the period of rest recorded in the Cuchilla level. The later 
terraces, sea cliffs, base levels, and modern coral reefs and savanna 
deposits of the south coast were then elevated. It is also evident that 
in this later period elevation was intermittent, accompanied by slight 
pauses. It is difficult to exactly fix the time of this latest elevation. 
It was certainly very recent, and a considerable period later than the 
old Yunque elevation. It cannot be older than late Pliocene, and it 
may or may not be in progress at present. 
It is not the province of this paper to discuss the history and origin 
of the Antillean sub-continent to which Cuba belongs, but I cannot 
refrain from presenting a few thoughts which may be of service to those 
who may consider this subject. 
The old metamorphic floor represents, beyond reasonable doubt, a land 
that existed probably in Cretaceous time, and much of its metamorphism 
and igneous extrusion took place in that period. Similar phenomena 
have been recorded in Santo Domingo and Jamaica. In fact, it is not 
proved that any rocks older than Mesozoic existed upon any of these 
islands. Similar disturbances and excessive vulcanism and metamor- 
phism are known to have been extensive on the Cordilleran region of 
the North American continent, including all of Mexico and the Cordil- 
leran region of the United States, which have been described by the 
writer and others, and lately most aptly termed by Lawson the Meso- 
zoic revolution.? 
As I have shown in a previous paper,? the marine waters extended 
across the isthmian region of the American continent, at least during 
the earlier half of Cretaceous time (the Comanche epoch). Whether 
this was by union of the two oceans, or by an eastward indentation of 
the Pacific, or vice versa, I am not prepared to say. It is certain, how- 
1 See the Journal of Geology, Vol. I. No. 6, September-October, 1895. 
2 The Cretaceous Formations of Mexico and their Relations to North American 
Geographic Development, American Journal of Science, April, 1893. 
