CRETACEOUS AND TERTIARY FORMATIONS. 21 



have not been able to find any certain explanation of these desig- 

 nations. 



Whitfield 1 in discussing the paleontological horizons of the 

 marl beds of New Jersey, speaks of "seven distinct horizons. 

 six of which may be classed as Cretaceous and one as Eocene,'* 

 which "conform very closely, if not exactly, to certain strati- 

 graphical lines, which were long since established by the State 

 Geologist * * *." These were 1) The Raritan clays; 

 2) The Camden clays at Fish House, containing 12 species of 

 Unionidae; 3) The micaceous clays at Crosswicks Creek below 

 the Lower Marl bed; 4) the Lower Marl bed; 5) the Middle 

 Marl bed; 6) the Cretaceous portion of the Upper Marl bed 

 ( Manasquan marl), and 7) the Eocene portion of the Upper 

 Marl (the Shark River). Possibly it is some such correlation 

 as this that Cope had in mind. If so, his "Greensand No. 2" 

 must be relegated to the Pleistocene as it is now known that the 

 Unionidce clays at Fish House are not Cretaceous but Pleisto- 

 cene ; Greensand No. 3 may include the Merchantville, Wood- 

 bury, Marshalltown clays and certain clayey layers in the English- 

 town and YVenonah sands. Greensand No. 4 would correspond 

 to the Navesink marl, but might also include certain phases of-, 

 the Red Bank sand. 



1 Whitfield, loc. cit. p. 19, 20. 



