20 CRETACEOUS PALEONTOLOGY. 



conclusion the writer has been opposed to Clark, who first in- 

 cluded the "yellow sand" in the Upper Marl (Manasquan) and 

 later in the Miocene. Weller's paleontological work has con- 

 firmed the correctness of its correlation with the limesand, a con- 

 clusion in which Clark now joins. 



The writer also mapped in detail the occurrence of a bed of 

 indurated marly sand (Tinton), occurring- in the upper part of 

 Cook's Red Sand, which previous workers had not separately 

 treated. Owing to its hardness, it is a somewhat conspicuous 

 stratigraphic unit and hence was mapped separately, although its 

 areal extent is somewhat limited. 



The correlations and mapping worked out by the writer were 

 based almost entirely upon the physical and lithological charac- 

 ter of the beds. Subsequent study of the faunas by Weller has 

 shown that most of these lithologic units are also faunal units, 

 at least of a minor grade. However, in the case of the Wenonah 

 sand, as the writer mapped and described it, the faunal classi- 

 fication does not entirely agree with the lithologic. The writer 

 holds that in this case the economic considerations involved de- 

 mand that the lithologic classification is the one which should 

 be represented on a geologic map, rather than one based on the 

 less evident and less familiar facts of paleontology. 



Somewhat later, in connection with the study of the clays and 

 clay industry in New Jersey, Kummel 1 studied the stratigraphy 

 of the lower Cretaceous beds of the State, and with Knapp's com- 

 pleted maps in hand examined more or less in detail the higher 

 formations, his observations substantiating in the main those of 

 Knapp. In this report Kummel grouped the formations in a 

 three-fold division, following Cook in this respect, and indicated 

 that in his opinion, that arrangement was best suited to bring out 

 the lithological and economic characteristics of the New Jersey 

 Cretaceous. The stratigraphy as interpreted by Knapp and Kum- 

 mel in that report is shown in the accompanying Table III. 



'Geol. Surv. N. J., Final Report, vol. vi. (1904.) 



