PAPERS ON BIOLOGY AND AGRICULTURE 143 



replaced by the modem bison. Two musk ox are re- 

 corded from the state, a very old one, Symbos cavifrons, 

 and the modern Ovibos moschatus that probably followed 

 the ice from his northern home. 



A peccary was fairly common here in the form of Plat- 

 ogonus compressus. His relative, the peccary of the 

 south, now lives in parts of Texas and south of the Eio 

 Grande. 



The tapir was of an old type, Tapirus haysii. The 

 tapir fauna of the present day is to be found only in Cen- 

 tral and South America and in Southern Asia. 



Of the large horse group only two have been found in 

 this region, Equus complicatus and Equus fraternus. 

 They died out with the rest of the horses and left their 

 bones in the state. 



The elephants, of African origin, came over early in 

 the Tertiary and scattered over the Americas. Three of 

 this magnificent group lived in this region, Elephas prini- 

 igenius or the mammoth, Elephas columbi, a much larger 

 type, and the swamp loving Mastodon of the wet, wooded 

 regions, Mastodon americanus. At the present time the 

 elephant is to be found only in Africa and Asia. 



All of the larger members of the deer group were to 

 be found in this region, the elk, moose, the caribou, and 

 the smaller Odocoileus virginianus. Although all of 

 these forms are still to be found, they are far removed 

 from this central region. 



The bear left sometime before 1800, and has been 

 driven gradually to more uncivilized parts where he is 

 not in such close contact with man. 



One very interesting mammal, Castoroides, a large 

 beaver-like animal, lived here as the original deforesting 

 agent. As large as a small black bear in size, his on- 

 slaught on the trees must have been terrific. If the 

 modern beaver can cut a cottonwood four feet in diame- 

 ter, what must have been the size of the trees that this 

 fellow would cut ? This form was quite widely scattered 

 over the country. 



This picture of the shifting of the faunas delights the 

 students of geographical distribution and enlivens the 

 labors of the palaeontologist and the student of compar- 



