136 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



of the archipelago are of cretaceous age, and are observed in 

 Trinidad, Jamaica, the Virgin Islands ; possibly also in Porto 

 Kico, San Domingo, and Cuba. The cretaceous formation of 

 Trinidad appears to be older than that of Jamaica and the 

 Virgin Islands, and is, perhaps, of the Neocomian period, 

 while that of Jamaica is probably equivalent to the European 

 hippurite line. 



The fact that most of the rocks of the cretaceous formation 

 in the "West Indies are of an igneous nature would tend to 

 show that they were heaped up in a period of great volcanic 

 activity, and as the miocene formation in several places covers 

 the highly disturbed cretaceous rocks in almost horizontal 

 and undisturbed beds, it is inferred that prior to the miocene 

 time cretaceous rocks were raised to a mountain chain, run- 

 ning from east to west, and parallel with the northern coast- 

 line of South America. 



Eocene beds occur in Jamaica, in Trinidad, and St. Bar- 

 tholomew ; probably also in St. Martin, Antigua, Guadaloupe, 

 Barbadoes, etc. These may be considered as equivalent to 

 the lower or middle eocene of Europe. They embrace to a 

 great extent igneous or metamorphic rocks, proving the ex- 

 istence of volcanic agencies at tjiat time. 



The miocene formation consists mostly of limestone or 

 marl, and is of enormous abundance, extending over large 

 spaces in Cuba, San Domingo, Jamaica, Porto Rico, and some 

 other islands. It is continued in the northern part of South 

 America and in Panama. Its fossil fauna has a close resem- 

 blance to that of Europe, and shows a great affinity to the 

 still living fauna of the Pacific and the East Indies. Some 

 of these fossils have their representatives still living in the 

 Caribbean Sea. The fauna of the miocene of the West Indies, 

 however, shows but little relationship to that of North Amer- 

 ica. The geological evidences in the West Indies tend to 

 prove that during the miocene period there was a connection 

 between the waters of the Atlantic and Pacific oceans by 

 means of a strait occupying the present position of the Isth- 

 mus of Panama, and also tliat there was probably a connec- 

 tion with Europe by means of an archipelago extending 

 across the ocean. 



From the thickness of the miocene strata of the West In- 

 dies, and their generally undisturbed position, we may infer 



