CORRELATION AND PALEOGEOGRAPHY 25l 



depend in part zoologically on a far more precise distinction and com- 

 parison of species than has yet been made ; an important piece of research 

 which is now in the hands of Dr. 0. P. Hay. Pleistocene life in Alaska 

 has been revlew^ed by Quackenbush^- (1909). 



Pleistocene correlation depends geologically on the relation of the 

 fauna to the six glacial and five interglacial stages which Chamberlin, 

 Salisbury, Calvin, and other authorities on Quaternary geology adopt. 

 It is obvious that if geologists succeed in correlating the American 

 glacial advances with those in Europe our paleontologists will secure the 

 means of correlating such interglacial faunae as are discovered with the 

 great pre-, inter-, and post-Glacial faunae of Europe. Such discoveries 

 in America now^ include only the first interglacial, or Aftonian fauna 

 (Calvin, 1909), and a sparse fauna of the second interglacial, or Yar- 

 mouth. Very precise determination of the species and mutations in these 

 and in other still to be discovered interglacial fauna will gradually clear 

 up these highly important problems. A virgin field of research awaits 

 the Pleistocene investigator. 



The zonal division into four stages suggested by Osborn is as follows : 



I. 



IF. 



III. 



IV. 



Plains Fauna. 



FOKEST FaINA. 



avoodlands and 

 Barrkn Gkounu. 



AVoODLAND AND 

 Pl INS. 



E'jnits, Onnelus. 



Equuit, Bison. 



Ovibos 



Cervus and many 



Paramylodun, J'laty- 



Megnlonyx. 



Ranglfer. 



modern species of 



gonus, Machserodus. 



Cenus, Alce.^i. 



Mastodon. 



mammals. 





Eacerutheruun. 



Elephas prim igenius. 





Non-arrivals: 



Non-arrivals: 



Non-arrivals: 



Disappearance of 



Deer [Cervus). 



Caiibou [Ranglfer 



. Few modern spe- 



horses, tapirs, 



Bear ( Ursus). 



Musk ox [Oi'ibos). 



cies of mammals. 



mastodons, and 



Goats [Oreamnus). 







mammoth. 



Sheep {Oi'is). 









Pre-Glacial and Ear- 



■ Interglacial. 



Late Interglacial. 



Post-Glacial. 



ly Interglacial. 



South America -^ 



The congelation of the mammal faunae of the northern continents is 

 long since settled in its fundamentals. Progress in the last decade has 

 been in the precision of detail, local and intercontinental. No one now. 

 questions the broader equivalence of epochs, the approximate position of 

 the greater formations in the time scale. 



22 L. S. Quackenbush : Notes on Alaskan Mammoth Expeditions of 1907 and 1908. Bul- 

 letin of the American Museum of Natural History, vol. xxvi. art. ix. March 24, 1009, pp. 

 87-130. 



^ Notes prepared by Dr. W. D. Matthew. 



XVIII — Bull. Geol. Soc. Am., Vol. 28, 1911 



