94 TERTIARY LAND ROUTES I'.ll'l tVEEX AMERICA \XD AFKK A. 



from the coast of Brazil, as Dr. Dall and Dr. \ errill have shown 

 — so the Tertiary marine invertebrate faunas of the Gulf States 

 ])robably originated in the Brazilian and Antillean waters. 



On the other hand, various recent researches have shown as 

 regards the supposed affinities of the Antillean and South Ameri- 

 can Cretaceous, Eocene, and Oligocene invertebrate faunas to 

 those of South-Western Europe and Northern Africa and India, 

 that although there are very few species in common, and others 

 bearing resemblances, yet the evclution of the faunas on the two 

 sides of the Atlantic was distinct. The si>ecies common to both 

 coasts were in some cases pelagic, as the South American 

 Cretaceous Ammonite, PulcheUia. which occurs in Colombia and 

 neighbour i-ng countries, and in the Alps, Roumania, and Asia. 

 3n other cases as Venericardia planicosta, we can easily suppose 

 the molluscs to have crossed xna the Greenland-Spitzbergen 

 route, especially when we recall the sub-tropical climate prevail- 

 ing in those high latitudes during the early Tertiaries. Or 

 these species may have been of northern origin and migrated 

 down the east and west coasts of the Atlantic. Some of the 

 resemblances have been found to lie parallelisms of develop- 

 ment, merely responses to similar environments, and not specific 

 identities. Moreover, in a number of cases species identifie<l 

 years ago with those of the eastern hemisphere have turned out 

 later when more material was obtained, not to be precisely the 

 same. For example, in 1887 Dr. C. A. White, in his fine mono- 

 graph on Brazilian fossils* identified a Turrit cUa from the Rio 

 Maria I'^arinha beds, Pernambuco, as I'ltrritcUa clicita described 

 by Stoliczka from the Cretaceous of Southern Indiaf. Since 

 then Professor G. D. Harris has monogra])he(l the Alabama Mid- 

 way$, and now it is clear that the true identity of the Brazilian 

 TurritcUa is not with the Indian species, but with Conrad's 

 Turritel'a lunncrosa, characteristic of the North American Lower 

 Eocene. 



There is, however, a TurritcUa in the lowest fossiliferous 

 bed on Soldado, which is extremely close to Stoliczka's shell, 

 differing mainly in its less slender form, and I have named it 

 elicitatoides. But Dr. Dall once pointed out to me an interesting 

 ■''act shown by the rich and exquisitely preserved Florida Oligo- 

 cene shells, namely, that in successive horizons there often come 

 repetitions of certain types of sculpture. Now this must indicate 

 a ready response to similar external conditions, a repetition of 

 physical conditions causing a repetition of sculpture. And it 

 would seem likely that the resemblance between the Soldado 

 and Indian shells should be explained in this way. 



Those who advocate the relationships between the South 



* " Arch, do Museu Nac. do Rio de Janeiro" (1887), pp. 162-163. pl- 

 XVIII, figs 6. 7- 



t "Pal. Indica, Geol, Surv. India," Vol. II. p. 221. pl. XIV, lig. 3, 1868. 

 t " Bull, American Palaeontology," Vol. I. 



