CHAPTER XV. 



CLASSIFICATION AND CORRELATION 



OF THE CRETACEOUS FAUNAS 



OF NEW JERSEY. 



A critical analysis of the entire series of marine Cretaceous 

 faunas of New Jersey leads to the conclusion that but two major 

 paleontologic divisions can be recognized. Continued investiga- 

 tion of the faunas has shown that the recognition of four major 

 divisions, as proposed by Clark, 1 and as previously accepted with 

 some modifications by the writer, 2 does not properly represent the 

 true conditions in the history of the faunas. It has been shown 

 in the series of summary tables given in the preceding pages for 

 each of the faunas from the Cliffwood to the Tinton, inclusive, 

 how intimate are the relations between them all. Not one 

 of them but which contains a greater or less number of species 

 common to each of the others, and although different elements 

 are present in these faunas, which are developed in varying" 

 degrees in different members of the faunal series, yet the inter- 

 relationship between all is very close. From, the faunal point of 

 view the recognition of a Matawan division and a Monmouth 

 division in New Jersey is strictly arbitrary and unnatural. Some 

 species, to be sure, are restricted to the lower formations of the 

 series and others to the upper, but there is no assemblage of forms 

 which can properly be said to constitute a Matawan fauna and 

 another a Monmouth fauna, which are any more distinct in. 

 character than the faunas of successive formations. 



1 Matawan, Monmouth, Rancocas and Manasquan. 



2 Jour. Geol., vol. 13, pp. 71-84; Geol. Surv. N. J., Am. Rep. State Geol. for 

 1904, pp. 145-159. 



12 PAL (177) 



