J. E. Marr — Cambrian and Silurian Rocks. 



249 



!2! 



t-l 



> 



t-l 



ta 

 > 



a 

 o 



2! 



td 



r^ 



d 



< 



> 



o 



^ 





> 













tr^tr^^d 





g 



O 



sr ° — '^ 



!^ 



V^ 



p ^ ^^ 





p* 





i^s S^M 



K| 



K| 





d 



O 



CAMBEIAN. 



9 w. 



^ 2. 



LOWER 

 SILURIAN. 



B 



a" 



LOWER SILURIAN, or 

 CAMBRO-SILURIAN. 



SILURIAN. 



UPPER 

 SILURIAN. 



UPPER 

 SILURIAN. 



CAMBRIAN. 



LOWER 

 SILURIAN. 





CAMBRIAN. 



LOWER 

 SILURIAN. 



o 



cr' 





LOWER SILURIAN. 



UPPER 

 SILURIAN. 



UPPER 

 SILURIAN. 



UPPER 

 SILURIAN. 



CAMBRIAN. 



Ordovician. 



SILURIAN. 



SILURIAN 



H- *-! 



CO 3 



With this list before us, it is impossible to say that geologists are 

 agreed with regard to one or another classification. Nor are foreign 



