1 66 The Rocks of the John Day Valley. 



canic ashes, rough to the touch as ground 

 pumice stone, which must have fallen on that 

 lake in vast quantities. The purest was evi- 

 dently that which had fallen directly into the 

 lake, the less pure that which, first falling on 

 surrounding hills, had subsequently drifted 

 from them by the action of the winds and 

 waters and had become part of the lake sedi- 

 ment. 



Upon the hills that overlooked these lake 

 shores there lived three or four different 

 species of the horse family. Their remains 

 are easily distinguished, for the teeth are well 

 preserved and the teeth of the horse are well 

 marked. Almost as well marked as these 

 equine remains were some teeth that appar- 

 ently represented a member of the camel fam- 

 ily found there too, in a fine specimen of a 

 lower jaw silicified completely and in solid 

 rock. Fossil remains of other species also 

 giving a wide range of life record, were found. 



But the most remarkable thing about this 

 upper lake record is that which reveals the 

 way in which its history of this period wa? 



