3 The T c wo Islands. 



tions of these newly elevated materials until a 

 wave-washed sloping beach was made a pro- 

 gressive margin for each- island. 



It was on these sloping beaches that the 

 life struggle around these islands first com- 

 menced, and on comparing again the fossil 

 forms from each, the kinship of the two re- 

 gions becomes at once plain. 



Twenty years ago Mr. Day, of Eastern 

 Oregon, found a small group of fossil shells 

 on the elevated plateau between Canyon City 

 and Prineville. Two of these shells, one of 

 them a Pecten, the other a Pholodomya, were 

 finely preserved and soon found their place 

 in history. 



In time Shasta county, in Northern Cali- 

 fornia, was found to have a like exposure of 

 these Jurassic shells. 



Still later Mr. Huntington, of Baker 

 county, threw a flood of light on the extent 

 of the eastern island by obtaining another 

 group of fossil shells which proved to be well 

 defined Jurassic, found twenty-five miles north 

 of Burns. This searchlight was soon followed 



