RELATIVE AGE OF THE ROCKS OF DIFFERENT LOCALITIES. 413 



Tkias or Lias. 



American and Sailors canyons, California : 

 Daonella bed. 

 Ammonites bed. 

 Gryphsea bed. 

 Snow Mountain bed. 



Jura. 



Lower Jura or Liassian. 



Lower Lias. 



Inyo county, California 



Esmeralda county, Nevada 



Southwestern part of Star Peak range (?), Ne- 

 vada _ 



Esmeralda county, Nevada 1 



Taylorville, California j- Hardgrave sandstone. Upper Lias. 



Beaver creek, Oregon J 



Middle Jura or Oolite. 



T 1 '11 / Thompson limestone ) 



iayiorvnie <^ jyiormon sandstone \ Inferior Oolite. ^ 



Canyon of the Yellowstone J 



Upper Jura or Malm. 



Taylorville (Bicknell sandstone, Callovian).. ^ 



Black hills, Dakota t i-k ^ j- 



Red buttes, North Platte " ^^^^'^^ Oxfordian. 



Aurora, Wyoming , 



Taylorville, Hinchman tuff, Corallian Upper Oxfordian. 



Mariposa basin, zone of Cardioceras dahinm (?) 

 Mariposa basin, zone of Perisphindes uirgala- 



M^^Mn,zxnie of' Av^eUaerrb^^^ f^''^h%ll!Zt^^'^^' Oxfordian to 



arcuata (?) 



Colfax basin, with Belemnites and Perisphinc- 



tes colfaxi and miihlbachi 



Descriptions. 

 fossils of american and sailors canyons, california. 



ammonitin^. 



These fossils,* although abundant and sufficiently well preserved 

 otherwise, show no suture lines, and it is therefore not considered advis- 

 able to descril)e them at present. 



♦The specimens were collected by Dr Curtice, of the United States Geological Survey, in July 

 1891, in shale beds of the American canyon, north side, about one-third of a mile east of American 

 Granite ledge, in a ravine. They were described by Dr Curtice as lying just beyond the Carbon- 

 iferous in going up American canyon and before arriving at New York canyon, in what he has 

 called the Monotis shales. 



