from the Observations of himself and Mr. Clemson. ?7 



small pea. They were unequally distributed, and in some spe- 

 cimens but few can be observed. The shells were in almost 

 every instance enveloped in crystallized carbonate of lime. 



During subsequent researches we ascertained that the red 

 rock was not interstratified with the white limestone, but oc- 

 cupied the spaces formed by ancient open fissures, sometimes 

 a few inches only in thickness; but in one instance, within fif- 

 teen feet only of the summit, it was exhibited of the breadth 

 of fifty feet, and of a thickness varying from ten to thirty. 

 This mass was evidently composed of a numerous series of 

 <leposits, having different tints, and being more or less earthy 

 or crystallized, emitting an offensive odour when broken. 



It was not until after two or three visits to this mountain 

 that we traced satisfactorily the extent of these insulated shelly 

 deposits, acquired a knowledge of their origin, and per- 

 ceived the process by which they were consolidated. It be- 

 came evident, on comparison, that these univalves, which were 

 as abundant as in any deposit we have seen, were referrible to 

 land genera, such as exist in profusion among the rocks of the 

 same mountain, amounting to eight or nine species at least. 

 The inhabitants of these shells retire into the open fissures 

 and caves, and in some instances are probably carried into 

 them ; and the dead and unoccupied shells lie in vast num- 

 bers in such places, in every instance mixed with the red 

 earth, similar in colour to the more earthy portion of the con- 

 solidated rock. These caves are resorted to by multitudes of 

 bats, and beneath the holes in the roof where they most con- 

 gregated I observed heaps of the dung of these animals, of a 

 bright red colour, as if derived from some seeds or berries 

 upon which they had fed. It is possible that a portion of this 

 red colour of the earth and of the consolidated rock was de- 

 rived from this source, and probably the globular bodies to 

 which I have referred originated in the same way. 



By the stalagmitical process the shells, together with other 

 extraneous substances within its influence, become enveloped 

 in crystallized carbonate of lime, and the operation of infiltra- 

 tion may be seen slowly but uniformly proceeding, until caves 

 and fissures of considerable size are wholly filled up with the 

 new mass, and are consolidated with the older limestone. 

 Sometimes the mass contains brecciated fragments of this white 

 limestone. It approaches in colour to the osseous breccia of 

 Gibraltar. We had little hope of discovering bones of large 

 animals in the caves of an island which contained on its dis- 

 covery no quadruped larger than the Indian rat. But we 

 met with fragments of bones which we referred to the Hutia, 

 or large Indian rat of the island, which is nearly the size of 



E2 



