74 /. Hall on the Cretaceous Strata of the United States, 



giostoma dumosum and Numrnulites Mantelli {Orhitoides Mantelli). 



This rock is now regarded as belonging to the older tertiary 



formations. 



The medial division was regarded as contemporaneous with 



the white chalk of Europe, 



The lower division embraced the " ferruginous sand deposits 

 of the Atlantic states, extending from Martha's Vineyard to 

 South Carolina and Alabama and into Mississippi, Arkansas and 

 Missouri" 



These strata were at that time regarded as contemporaneous 

 with those which lie between the white chalk and Oolite in 

 Europe. 



The foregoing subdivisions were proposed by Dr. Morton in 

 some " additional observations" appended to his "Synopsis of 

 tlie Organic Remains of the Cretaceous group of the United 

 States," and pubhshed in the Journal of the Academy of Natu- 

 ral Sciences in 1842. Accompanying this classification of the 

 cretaceous formation is a list of fossils from each of the subdi- 

 visions, including all those which had been described up to that 

 period. 



Prof Rogers^ in his Report upon the Geology of New Jersey 

 in 1840, proposed a division of the cretaceous formation of the 

 state into five members. These subdivisions, however useful 

 they may have been topographically, are Dot accompanied by 

 the palaeontological evidence necessary to enable us to determine 

 their value as distinctive groups, or to aid us in a comparison 

 with the sequence in other localities. 



More recently the investigations made during the geolo^cal 

 survey of the state of Kew Jersey, have thrown further light 

 upon the order of succession, and the lithological character of 

 the members composing the greensand formation of New Jersey. 

 The section given by Prof Cook, which has been verified by 

 borings in several places, leaves no doubt that we have now ar- 

 rived at a knowleage of the true relations of the dijBferent mem- 

 bers of this period as developed in NewJereey; and it is the 

 more interestmg since it enables us to show the true position of 

 certain well marked and widely distributed cretaceous fossils, in 

 relation to others which approximate in character to tertiary 

 types. 



The following section gives the expression of all that is at 

 present known regarding the order of succession among the mem- 

 bers of the system as they occur in southeastern New Jersey.* 



F 



Jersey Geological Survey, who gives some additioaal informat 

 published in his Geological Report. 



