258 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA 



foraminiferal zones instead. The Paleocene is divided on the basis of its planktonic 

 Foraminifera into the following three zones ; the Globorotalia compressajGlobigerina 

 daubjergensis Zone, the Globorotalia angulata Zone and the Globorotalia velascoensis 

 Zone. These are taken to represent the Lower Paleocene (or the Danian), the Middle 

 Paleocene, and the Upper Paleocene respectively. The assignment of either of the 

 last two zones to the Montian, Thanetian, Sparnacian, Landenian or Ilerdian, as 

 suggested by various authors, is rather arbitrary, and is not based on proper correla- 

 tion with the type sections. 



7. The term " Ilerdian " should be dropped from Paleocene stratigraphy as it is 

 very misleading. 



8. The Paleocene-Eocene boundary is marked by the complete disappearance of 

 Globorotalia velascoensis velascoensis (Cushman) and its associated fauna, by the 

 first appearance of Globorotalia bollii sp.nov., and by the flood of Globorotalia wilcox- 

 ensis Cushman & Ponton. 



9. The basal Eocene is marked by the Globorotalia wilcoxensis Zone. The 

 relationship between the Ypresian and the Cuisian is not yet completely understood ; 

 the term Ypresian appears to be more appropriate inasmuch as the type Ypresian 

 alsc ludes the Cuisian, but the fact that the planktonic Foraminifera in these 

 type stages are not correctly known, neccesitates the temporary abandonment of 

 these terms. 



