MUSEUM OF COMPARATIVE ZOOLOGY. 247 



taceous, reported by De Castro aiid occasionally seen by me in this old 

 complex, testifies tliat in Pre-Tertiary time the old metamorphic floor 

 protruded above the level of the sea as a land area, during a period of 

 active vulcauism. 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 tiiat place and San Pedro they are 

 eroded through down to the underlying clay formation, which extends 

 from thei'e 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 tliese 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 avound 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 Tertiai-y 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. 



