FOSSILS OF THE 11ECENT rOUMATlONB. 899 



Cerro oiMeapire; on the [Alpine] limestone of Cumanncoa; 

 between Porto Cabello and the Kio Guayguaza ; as well as 

 in the valleys of Aragua ; on granite ; on the western de- 

 clivity of the hill iormed by Cabo Blanco, on gneiss; and 

 in the peninsula oi Araya, on saliferous clay. But this is 

 perhaps merely the effect of apposition.* Il we would range 

 the different members of the tertiary series according to the 

 age of their formation, we ought, I believe, to regard the 

 breccia oi Cabo Blanco with fragments of primitive rocks, as 

 the most ancient, and make it be succeeded by the arena- 

 ceous limestone of the castle of Cumana, without horned 

 silex, yet somewhat analagous to the coarse limestone oi 

 Paris, and the iresh-water soil of Victoria. The clayey 

 gypsum, mixed with calcareous breccia with madrepores, 

 cardites, and oysters, which I found between Carthagena 

 and the Cerro de la Popa, and the equally recent limestones 

 of Guadalope, and Barbadoes (limestones filled with sea- 

 shells resembling those now existing in the Caribbean Sea) 

 prove that the latest deposited strata of the tertiary forma- 

 tion extend far towards the west and north. 



These recent formations, so rich in vestiges of organized 

 bodies, furnish a vast field of observation to those who are 

 familiar with the zoological character of rocks. To examine 

 these vestiges in strata superposed as by steps, one above 

 another, is to study the Fauna of different ages, and to com- 

 pare them together. The geography of animals marks out 

 limits in space, according to the diversity of climates, which 

 determine the actual state of vegetation on our planet. The 

 geology of organized bodies, on the contrary, is a fragment 

 of the history of nature, taking the word history in its 

 proper acceptation : it describes the inhabitants of the earth 

 according to succession of time. We may study genera 

 and species in museums, but the Fauna of different ages^ 

 the predominance of certain shells, the numerical relations 

 which characterize the animal kingdom, and the vegetation 

 of a place or of a period, should be studied in sight of 

 those formations. It has long appeared to me that in the 

 tropics as well as in the temperate zone, the species of uni- 

 valve shells are much more numerous than bivalves. From 



* An-nicht Aujlageritny, according to the precise language of th* 

 geologist* of my country. 



