1866.] GUPPY WEST-INDIAN TERTIARIES. 577 



cies, nineteen have been found in Jamaica, and twenty-five in San 

 Domingo, leaving but seven now enumerated for the first time from 

 the Caribean Miocene. From this analysis it will be seen that it 

 would be difficult to separate the Cumana beds from the Caribean 

 Miocene, and at the same time that it is probable they represent 

 one of the highest stages of that formation. 



§ 5. The Age of the Caribean Miocene. 



The affinities of the organic remains of the Caribean Miocene are 

 stronger with foreign species, both Midtertiary and E-ecent, than 

 with the existing fauna of the West Indies, indicating an antiquity 

 somewhat greater than would be adduced for them from the propor- 

 tion of extinct species, which I cannot consider greater for those 

 deposits I have classed as Upper Miocene than 80 per cent. In ray 

 paper on the Jamaican fossils I showed that the proportion of recent 

 species was 20 per cent. ; and by comparing the list I have given of 

 the San Domingan MoUusca, it wiU be seen that a similar proportion 

 obtains for them. In explanation of the discrepancies between my 

 list and previous estimates, I may remark that I cannot consider the 

 Pyrida consors of Sowerby to be distinct from the P. melongena of 

 Linne, nor the Ostrea Haitensis of Sowerby to be specifically distin- 

 guishable from the 0. virginica of GmeHn. Mr. Carrick Moore, in 

 the latter of his papers on the San Domingan fossils, reduced the pro- 

 portion of living species to 8 or 9 per cent. ; but this was done by 

 assigning certain of them to deposits of a later period. However, as 

 those species haye been found in Jamaica and elsewhere associated 

 with the characteristic fossils of the Caribean Miocene, I have not 

 felt myself justified in excluding them from the Haitian list. 



§ 6. Other Tertiary Formations in the West Indies. 



There exists m several of the West-Indian islands undoubted later 

 Tertiaries containing a very large proportion of recent species. This 

 seems to have been partly the cause of the confusion as to the age 

 of some of the fossils. Our knowledge of the geology of these islands 

 being so limited, some authors have inferred that all the fossils were 

 derived from the same formation. It is often difficult to distinguish 

 between the rocks composing the newer and older formations, both 

 being sometimes white calcareous deposits, and the newer frequently 

 being the hardest. 



The Tertiary formations of Guadeloupe have been studied by 

 Duchassaing, who divides them into JSTewer and Older Pliocene and 

 Miocene*. To the first of these are assigned, amongst other depo- 

 sits, those containing human remains. From the Older Pliocene 

 Duchassaing obtained twenty-six speciesof Mollusca, many of which 

 he identified with recent species f. He records from the same beds 

 thirteen Echinoderms, of which seven are extinct. It would seem 

 that these results are somewhat discordant ; and when we consider 



* Bull. Soc. Geol. de France, ser. 2. vol. iv. (1847) p. 1093. 

 t Ibid, ser, 2. vol. lii. p. 753. 



