mmmmmmmmwmmmmam 



mm 



CONTRIBUTION TO THE PALEONTOLOGY OF TRINIDAD. 35 



presumably carried by oceanic currents corresponding to the present Gulf Stream 

 eastward; but the spread of the other genera cannot thus be accounted for. 

 Possibly we have in these instances cases of parallelisms of development. 



Recent and 

 Quaternary. 



Oligocene 



South America. 



Molluscan fauna northward 



from the La Plata. 



Eocene. 



Cretaceous. 



Carbonifer- 

 ous. 



Devonian. 



Silurian. 



Upper Oligocene faunas of Cumana, 

 Trinidad, Jamaica. 



Lower Oligocene faunas of San Fernando 

 and Manzanilla, Trinidad. 



North America. 

 Molluscan fauna southward 

 from Cape Hatteras. 



Lignitic fauna of Soldado Rock, Gulf of 

 Paria. 



Midway fauna of Soldado Rock and 

 Pernambuco. 



Cretaceous faunas of Venezuela and 

 Colombia. 



Faunas of the Amazonian Valley in 

 Brazil, Bolivia and Peru. 



Erere" formation, Brazil. 

 Maecuru beds, Brazil. 



Brazilian and Venezuelan Silurian faunas 

 (Upper formation). 



Brazilian Silurian faunas (Lower forma- 

 tion). 



Upper Oligocene of Florida, 

 beds, Chipola marls.) 



(Tampa silex 

 Lower Oligocene of Vicksburg, Mississippi. 



Lignitic fauna of Alabama and other Gulf 

 States. 



Midway fauna of Alabama and other Gulf 

 States. 



Cretaceous of the southwestern United 

 States and Mexico. 



Coal measures of the western United States. 

 (More than half the species being 

 identical.) 



Onondaga of the United States. 

 Oriskany of Alabama, etc. 



Niagaran of the United States. 



Clinton and Richmond of the United States. 



As above noted, the Oligocene faunas of Cumana, Trinidad, and the Antilles 

 in general, show close resemblances to the recent fauna of the west coasts of 

 Central America and of northwestern South America. This is due to the pre- 

 Oligocene free waterway over the Isthmus from the Caribbean to the Pacific. 



Regarding the resemblances of the Trinidad and other Antillean Oligocene to 

 that of southern France, the writer's observations of Tertiary forms in general 

 are the same as those of M. Douville for the South American Cretaceous, — 

 namely, that although the European and American formations include a very 

 few species in common and have a certain air de famille, their evolution was 

 distinct. 7 



Studies by Drs. Dall and Verrill of the living molluscan and coral faunas of 

 Florida and the West Indies indicate that the present faunas on the shores of the 

 Gulf Coast of the United States came originally from the coast of Brazil. And, as 

 Dr. Branner has already suggested, it seems very probable that the Tertiary 

 faunas of the Gulf States may have also originated on the Brazilian and Antillean 

 shores. The Soldado Eocene fauna is a strong argument in favor of this hy- 

 pothesis. 



7 Ann. de la Soc. Royale Zoologique et Malacologique de Belgique, t. XLI, pp. 142-155, 1906. 



