DEVONIAN SYSTEM: WETWIN SHALKS. 



25 i 



Wetwin Fauna — continued. 



DEVONIAN OF 

 AMERICA. 







Lower. 



Mid-1 



DLE 



Upper. 







Helderberg Gr. 



Corniferous Gr. 



I Hamilton Gr. 



Portage Gr. 



Chemung Gr. 



Europe. 



Remarks. 







X 









• 









X 

















X 







X 

 X 



M. Dev., Europe. 



Waverly Sandst. 

 =( L. Carb.), 

 America. 





X 



X 

 X 



• • 







Dev., Rhine. 





