DISTRIBUTION OF AMMONITES. 



1G7 



we travel southwards we find it ever later in point of time. The following diagram 

 will show this matter clearly : 



Name of Beds. 



Haresfield- 

 Wotton 

 District. 



Little 

 Sodbury. 



Midford, 

 near IJatli. 



Dorset- 

 Somerset 

 District. 



Opalinum. 







Absent ? 



Limestone 





Moorei. 



ol 



/• 



Absent ? 





Dumortieria. 



V^ 







r 



Dispansum. 







#^ 





Striatulum. 







As 



A •.""> 



^v 



/ 



Variabilis. 











Commune. 







V? 







10 miles 

 wide 



8 miles 

 further 



12 miles 



further 



36-50 



miles 

 further 



Total distance about 80 miles. 



For further particulars concerning the correlation of the Cotteswold, Midford, 

 and Yeovil Sands, and for additional sections I must refer the reader to my paper 

 on these deposits in the ' Quarterly Journal Geol. Soc.,' vol. xlv, pp. 440 — 474, 1889. 



The annexed table will show how some of these same deposits are found in the 

 Yorkshire and Northampton districts, as well as in the Ootteswolds and south 

 of the Mendips. 



My knowlege of the Yorkshire strata is derived from a collection of Ammonites 

 kindly forwarded by Mr. Hudleston, F.R.S. No species of Ammonites indicative 

 of the horizons of the Opalinum- and Moorei-heds, as now defined, were found ; but 

 these strata may possibly be represented, either in the top of the Yellow Sands or the 

 bottom of the overlying Dogger. Ammonites labelled " from the Yellow and Grey 

 Sands" indicate the horizon of the Dumortieria-heds; while representative species of 

 the Dispansum-, Striatulum-, and Variahilis-hed^ arc found in the black " Striatulus- 

 shales." 



