THE UPPER CRETACEOUS OF NEW JERSEY 73 



These three systems of classification have been arranged side by 

 side in the accompanying tables, in order that they may be easily 

 compared one with the other. 1 At the time of publication of Cook's 

 classification, although a large number of Cretaceous fossils had 

 been described from New Jersey, little was known of the actual 

 distribution of the fossil species in these beds, except in the case of 

 the conspicuous shell beds which can be recognized continuously 

 across the state. Cook's classification may therefore be considered 

 as being based almost exclusively upon the lithologic characters of 

 the beds. Before Clark's classification was proposed, however, 

 Whitfield's 2 two important volumes upon the paleontology of the 

 Cretaceous formations of New Jersey had been published, and Clark 

 gives long lists of fossil species in his papers as representative of the 

 faunas of his major divisions, so that his classification was founded, 

 at least in part, upon paleontologic data. Knapp's subdivisions of 

 the "clay-marl" series are professedly based upon the lithologic 

 characters alone. 



During the field seasons of 1903 and 1904 the writer has been 

 engaged in an investigation of the paleontology of these Cretaceous 

 beds and has accumulated a large amount of information in regard 

 to the faunas of the successive formations, especially those of the 

 "clay- marl" series, and in the following pages an attempt will be 

 made to point out the bearing which this new evidence has upon the 

 classification of the formations and faunas. 



In his Matawan division, Clark has recognized two formations, 

 the Crosswicks clays and the Hazlet sands. The Crosswicks clays 

 correspond exactly with Cook's "clayey green sand," and with 

 Knapp's two formations, the Merchantville clay-marl and the Wood- 

 bury clay; while the Hazlet sands correspond in Monmouth County 

 with Cook's "laminated sands" and with Knapp's two formations, 

 the Columbus sand and the Marshalltown clay-marl, as well as with 



1 In this table Cook's classification of the beds in Monmouth County is recognized. 

 His understanding of the stratigraphy in the south was incomplete, and in that por- 

 tion of the area he considered Knapp's Marshalltown formation as the equivalent of 

 the "lower marl" and the Wenonah as the equivalent of the "red sand," the true Red 

 Bank sand and the Tinton beds being absent there. 



2 Paleontology of New Jersey, Vols. I and II; also Monographs of U. S. Geological 

 Survey, Vols. IX and XVIII. 



