Vol. 



•] 



OF THE MID-COXTESWOLDS. 



459 



and that there is practically nothing below it ; while at Notgrove 

 Station there is 18 feet 1 inch of rock above this horizon, and 

 14 feet 9 inches below it. This at any rate explains why Notgrove 

 is the more prolific below. 



Table VIII. 



Diagrammatic Table to show the sequence in the acmes of develop- 

 ment of various species of brachiopoda — the greatest divergence in the 

 lines indicating the acme in each case. 



3 



q Base of 

 O. M. at 

 the Frith. 



Base of 

 O. M. at 



Notgrove 

 Station. 



Note. — Terebratula fimbria and Zeilleria Leckenbyi are found in the Pea- 

 grit of the Stroud district; and T. fimbria, in its aged form, probably ascends 

 higher than is shown here. The development would be more correctly repre- 

 sented by curved lines, but at present the data collected are not sufficient. 



From further comparison of these sections it will be seen that the 

 succession of the brachiopod-faunse corresponds exactly. At neither 

 locality is there any lithological deposit similar to the Upper Free- 



