Geol. Mag. 1922. 



lb 



Plate XII. 



\ 



(T^:^^ 



la 



/ 



'W 



'/; 



„^^ 





/ 



^ 



•• \ 



;/ 



-y 



E. T. Talbot, del. 

 To face p- 275.] 



2b 2c 



Lower Devonian Mollusca. 



2a 





