DEVONIAN SYSTEM : WETWIN SHALES. 



253 



Wetwin Fauna — concluded. 



DEVONIAN OF 

 AMERICA. 



Europe. 



Remarks. 



Lower. 



Mid- 

 dle. 



Upper. 



Helderberg Gr. 



Corniferous Gr. 



Hamilton Gr. 



Portage Gr. 



Chemung Gr. 













M. Dev., Devonshiie. 













X 



" 











X 









X 











" 









X 





















• • 



Probably the der- 















mal spine of 















an Acanthoid 















fish. 



