YORKSHIRE TYPE AMMONITES 



Mar. 

 1910 



TABLE V I—STRATIGRAPHY 



(Stages, Zones, and Yorkshire Lias Strata) 



Stage 



Zone 



Simpson's Divisions 

 (1884, ix — xxiii) 



Stratal Terms ( Yorkshire) 



H Pleuromya beds 

 X ^Modiola beds 



^Iii Jur. Time, Quart. Journ. Geol. Soc. liv, 18 

 ought really to be r-ckoneci as Trias. 



442, it was suggested that the strata of Hettaiigian 



) 

 I 



