MfWfflfi 



mimm 



91 



CONTRIBUTION TO THE PALEONTOLOGY OF TRINIDAD. 33 



White, Calyptraphorus chelonitis White, Fasciolaria? (Mazzalina) acutispira 

 White, Turritella sylviana Hartt, Nautilus (Enclimatoceras) sowerbyanus White 

 non Orb., Gryphcea trachyoptera White, Cucullcea hartti Rath. . . . with Gulf 

 State species." 



But in Dr. Branner's latest publications on this subject, his faith is shaken 

 in the Tertiary age of the Maria Farinha beds largely because of the reported 

 discovery of a Cretaceous cephalopod on the island of Itamarica which lies off 

 the Pernambuco coast. 



Dr. Derby, State Geologist of Brazil, is now also more strongly disposed to 

 regard the Maria Farinha and related faunas of nearby localities as Cretaceous. 

 In his latest article on the subject he writes: "The geological horizon of the 

 beds with faunas of Tertiary aspect is doubtful, but at present the preponder- 

 ance of evidence seems in favor of a Cretaceous age." 



In view of this difference of opinion, and the uncertainty of the age of the 

 Maria Farinha and related Brazilian faunas, the discovery of the Midway beds 

 on Soldado Rock is most illuminating. On that islet, as shown in the preceding 

 pages, we have found typical North American Midway species together with 

 characteristic Maria Farinha forms, and also species common to all three locali- 

 ties — Alabama, Soldado, and Maria Farinha. 



By this commingling of species Soldado Rock links the Alabama basal Eocene 

 fauna with that of Maria Farinha, Brazil. Thus the age of the Pernambuco 

 beds (Maria Farinha, Olinda, and Ponto das Pedras formations) is established 

 as Midway Eocene. 



AFFINITIES OF SOUTH AMERICAN EXTINCT FAUNAS. 



Great stress has been laid on the resemblances of the ancient forms of life 

 of South America to those of contemporaneous times of the Old World. Rela- 

 tionships have been established between the South American faunas and those 

 of France, Spain, Malta, Morocco, Egypt, Syria, India, and South Africa; but 

 until Dr. Derby's work on the Paleozoics of Brazil little was said of the faunal 

 relationships of the two Americas. In fact it was generally supposed that hardly 

 any communication had taken place between the species peopling North and 

 South America. 



To account for the similarity of faunas in the eastern and western hemispheres, 

 and to render possible the migrations of species not pelagic, authors have bridged 

 the ancient seas by imaginary continents. 



The most famous of these is Atlantis, which furnished a route passing north- 

 eastward and eastward from the island of Trinidad to southern Europe and north- 

 ern Africa. This land is thought by some to have been a continent, by others 

 an island chain. Unfortunately for this hypothesis, about which is woven the 

 charm of Greek and Egyptian tradition, there lie in the present bed of the Atlantic 

 several very deep basins (as the Virgin Islands deep) in the line of the hypothetical 

 land bridge. 



3 JOURN. ACAD. NAT. SCI. PHILA.. VOL. XV. 



