804 GEOLOGY 



Dinocerata. The animal was about the size of a sheep, and had 

 but a short career. 



The ruminants seem to have been introduced or foreshadowed 

 by the Tragulidce (chevratains) , now represented in Farther India 

 by a slender little ruminant, isolated and scarcely known, the 

 Tragulus, "the scarcely altered survivor of a great tribe whirl) 

 nourished abundantly in Europe, and less so in North America, 

 before the typical and fully differentiated ruminants had made 

 their appearance" * Many of the foregoing types were present also 

 in Europe, where there were types not now known in America. 



The marine life. If the Vicksburg formation is regarded as 

 Oligocene, the general aspect of the Eocene sea life remained un- 

 changed. In the later stages of the Oligocene, provincialism 

 became pronounced and the correlation of beds, even in the same 

 province, has been the subject of much difference of opinion. 1 ' By 

 this time, the foraminifers had declined greatly, and the fauna was 

 overwhelmingly mollusc an. 



On the Pacific coast, the Oligocene fauna shows closer relation 

 to the Miocene fauna than to that of the Eocene, and suggests a 

 climate transitional between that of the Eocene and that of the 

 Miocene. 3 



1 A. Smith Woodward, Vert. Pal., p. 360. 



2 Maury, Bull. Am. Pal., No. 15, Cornell Univ., 1902. 



3 Arnold, Jour. Geol., Vol. XVII. 



