from the Observations of himself and Mr. Clemson. 25 



posed surfaces are honeycombed and have sharp projecting 

 points as in the coral rock of the coast. 



Upon the skirts of most of these mountains are tufaceous 

 deposits, covering the surface; which calcareous tufa has been 

 derived from the decomposition of the rock, and is brought 

 down by the numerous springs which descend the hills. This 

 soft tufa incloses various extraneous substances, and contains 

 beautiful impressions of leaves and vegetables. 



Organic Remains, — In this rock traces of organic remains 

 are so extremely rare, that during months of examination but 

 two or three specimens came under our observation. They 

 were madrepores, the structure of which had been partly ob- 

 scured by crystallization, or by the change which the mass of 

 limestone had undergone. We have not observed the slightest 

 trace of a shell in this formation. It is possible that it may 

 have originally contained organized fossils which have been 

 obliterated by the modification to which the rock has evidently 

 been exposed. No mineral veins or substances were detected 

 in it. 



From the foregoing description it would appear that this 

 rock or marble is neither the white limestone with tertiary 

 shells, described by Mr. De la Beche as abounding in Jamaica ; 

 nor the compact lithographic limestone, sometimes containing 

 Pectens, Cardites, Terebratulae, and madrepores, described 

 by M. de Humboldt at the west end of the island of Cuba, 

 under the name of Calcaire [Jurassique?] de Gui?ies, which 

 we ourselves have had some opportunity of examining in the 

 vicinity of Havana. We conceive that it is more ancient than 

 those rocks ; and that it is contemporary with the Euphotides 

 and metalliferous serpentines of this region. 



It is a prevailing character of the Holguin and Gibara lime- 

 stone that it contains large masses of carbonate of lime of a 

 much later origin. These are accounted for, on the supposi- 

 tion that they were open fissures, cavities, and even large ca- 

 verns, which in process of time have been wholly filled by 

 stalagmitical infiltration. All these later deposits are of a 

 brick-red colour, remarkably fetid, and embrace vast quan- 

 tities of casts of land shells, occasionally intermixed with ma- 

 rine univalves, and with a few small bones, apparently of the 

 great Indian rat, one of the very few indigenous quadrupeds 

 of the island, and now inhabiting the same mountains. 



LaSilla. — This singularly-shaped mountain of white lime- 

 stone is about two miles long and one in breadth. Its sides, 

 towards the summit, are bare and perpendicular, so that only 

 at one or two points is it practicable to attain the top, by the 



Third Scries, Vol. 11. No. 61. July 1837. E 



