MUSEUM OF COMPARATIVE ZOOLOGY. 247 
taceous, reported by De Castro and -occasionally seen by me in this old 
complex, testifies that in Pre-Tertiary time the old metamorphic floor 
protruded above the level of the sea as a land area, during a period of 
active vulcanism. From their composition and occurrence there can 
be little doubt that they once formed an ancient land area of unknown 
size and relations, but certainly almost as large as the present island, 
which was partly or completely submerged during early Tertiary time. 
The Pre-Tertiary Sedimentaries. — Resting upon this metamorphic and 
igneous foundation at various places there is a formation of stratified, 
non-fossiliferous, sedimentary clays. These are older than the Tertiary 
limestone, and apparently immediately preceded them in origin. - They 
are not of great thickness, and are void of determinable fossils wherever 
I have observed them. In the Havana section, in the southern suburbs 
of the city, only a few feet are exposed beneath the old limestone in 
contact with the underlying tuffs. They are here green in color, and 
somewhat unctuous. 
In travelling overland toward Villa Clara, I found that the limestones 
extend beyond Colon, but between that place and San Pedro they are 
eroded through down to the underlying clay formation, which extends 
from there continuously east to Villa Clara, being best exposed at 
Esperanza. Here the railway has cut across alow anticline of clays 
which show well defined stratification planes and alternate strata of 
softer and harder beds. In general they consist of (1) an upper division 
of light colored, laminated, thinly banded clay, with persistent bedding, 
of which twenty feet are here exposed, and (2) a lower series of coarser 
beds, the harder persistent strata being loosely cemented and having a 
mealy consistency, with siliceous pebbles, while the alternate beds are 
laminated. About one hundred feet of these are exposed. These clays 
are folded and slightly faulted in places. 
I could find in these beds no fossil remains except one poorly preserved 
plant impression, a monocotyledon, which, with the general character of 
the material, gave the impression that these clays were deposited when 
the conditions of sedimentation around Cuba or in Cuba were far differ- 
ent from those of the present, and, to a certain extent, they indicate a 
previous land. I cannot say positively that the Esperanza clays are 
identical with the clays of Havana, but both occupy the same relative 
position between the Tertiary limestones and the metamorphic for- 
mation, and both are exposed by the erosion of the limestone from 
above them. 
De Castro refers these clays of Esperanza to the Cretaceous period, 
