534 



J. F. BLAKE ON THE UPPER 



10. — Map of the Tonne Valley south of Auocerre, 

 (Scale 1 : 240,000.) 



Cotteau divides the " Portlandian " rocks into two groups, the 

 upper of which is the zone of Pinna suprajurensis. This is very 

 well seen in the neighbourhood of Auxerre, and, like all these upper 

 rocks, is more fossiliferous as we go west. After the splendid 

 monograph by Loriol and Cotteau, it is superfluous to quote the 

 fossils, the great majority of which come from the upper portion. 

 "We need only compare the series with those seen before. In the 



