104 Introduction to Life of the Lakes. 



climate, and such without doubt was the cli- 

 mate of this region during the Eocene period. 



These fossil remains of forest trees of the 

 early Tertiary are so abundant and so finely 

 preserved that one is disappointed at the en- 

 tire absence of the bones of land animals from 

 these early records, their fossils being so abun- 

 dant here in the next age, the Miocene. 



But it must be remembered that at the 

 close of the Cretaceous period the mammalian 

 forms of life were but few and not widely dis- 

 tributed. A few small Marsupials and some of 

 still lower type, like the Duck Bill, were all 

 the world had of mammalian forms at that 

 time. 



Throughout the Cretaceous period the life 

 of the world's vertebrate animals was nearly 

 all reptilian the air, the land, the waters 

 teemed with reptilian forms of life. Mammals 

 of the two orders named had recently multi- 

 plied in North America as well as in Europe 

 and Asia, but it was not until after the great 

 mountain revolution of the Cascade barrier, 

 and therefore until the Eocene period, that 



