DEVONIAN SYSTEM: WETWIN SHALES. 



249 



Wetwin Fauna — continued. 



DEVONIAN OF 

 AMERICA. 







Lower. 



Mid- 

 dle. 



Upper. 







Helderberg Gr. 



Corniferous Gr. 



Hamilton Gr. 



1 



Portage Gr. 



Chemung Gr. 



Europe. 



Remarks. 













Dev., Poland. 















Dev., Knine. 













X 











X 















X 









A Devonian Am- 

 erican genus. 







X 









A Devonian 

 genus, Europe 

 and America. 



