6 NEW YORK ZOOLOGICAL SOCIETY. 



Along with this close resemblance, there seemed at first to be 

 also an appreciable inferiority in the size and beauty of the ani- 

 mals found in America, as compared with their Old World con- 

 geners. The puma and the jaguar were compared with the lion 

 and tiger, somewhat to the discredit of the former, and our black 

 bear, which was surprisingly numerous in Colonial times, suf- 

 fered also, when compared with the brown bear of Europe ; as 

 did our Virginia deer, in comparison with the European red deer. 



Later, however, when the frontier was pushed inland, and the 

 grizzly, the wapiti and the moose were measured by the 

 standards of the European brown bear, red deer and elk, no such 

 superiority could be claimed for thie Old World animals. In pro- 

 fusion of distinct types, however, North America, with its bison 

 and prong-horn, which, with the black-tailed deer and the wapiti, 

 virtually monopolized the great prairies and plains of the West, 

 could not vie with the magnificently diversified fauna of Africa, 

 with its hundred and more species of bovine antelopes, to say 

 nothing of other huge mammals. 



Close as is the relationship of Eurasian and North American 

 mammals, it never amounts to specific identity in the view of the 

 best American systematists, who differ in this respect from Euro- 

 pean do5Qistfe. The polar bear, and one or two smaller arctic 

 mammals ; fbfm the sole exceptions to the above statement. 



FIRST RADIATION. 



This poverty of animal life, both as to variety and number, 

 has not always existed, and a close study of the fossil mammals 

 of North America, of which we have a very complete record 

 from the Rocky Mountain region, demonstrates that there have 

 been two separate and distinct periods of great development and 

 radiation of mammals on this continent, together with several 

 clearly distinguishable immigrations from other lands. The last 

 of these immigrations from the Old World, by way of Behring 

 Straits, gave us the predominant members of our present fauna. 



The first of these periods of development is known as the 

 Puerco, and dates from the very dawn of the Basal Eocene, some 

 three million years ago. Deposits of this horizon are found in 

 New Mexico, and have revealed to us a large and varied fauna, 

 with true mammals, some as large as a Newfoundland dog. In 

 European beds of a corresponding age, the Cernaysien, a similar 

 but more limited fauna is found. 



This Puerco fauna flourished and radiated, paralleling many 



