EXTINCT ANIMALS 



top of the head (Fig. 104) and a pair of great 

 tusks formed by the enlargement of the upper 

 canine teeth. The horns are outgrowths of the 

 bone of the skull and were probably covered by 



Fig. 104. — Skeleton of Dinoceras mirabile, from the LTpper 

 Eocene of Wj'oming, U.S.A. 



hardened skin. The probable appearance of 

 this creature in life is shown in Fig. 105. 



A very interesting fact has been observed 

 about the brains of these most ancient big mam- 



148 



