Jlesozoic and Ccenozoic Geology and Fakeontologii. 47 



masses of chert, and also present some appearances of the green grains 

 so characteristic of the adjacent marls. 



The Cretaceous formation is unequivocally recognized in New 

 Jersey, from whence it nay be locally traced through Delaware, Mary- 

 land, Virginia, North and South Carolina, Alabama, Mississippi, Ten- 

 nessee, Louisiana, Arkansas and Missouri, it is also, probabl}', traced 

 to Long Island, and probabl}' forms the substratum of the islands of 

 Nantucket and Martha's Vinej^ard. "These various deposits" he 

 says, "though seemingly insulated, are doubtless continuous, or nearly 

 so, forming an irregular crescent, nearly 3,000 miles in extent; and 

 there is not only a generic accordance between the fossil shells scat- 

 tered through this vast tract, but in by far the greater number of 

 comparisons I have hitherto been able to make, the same species of 

 fossils are found throughout: thus, the Ammonites placenta^ Baculites 

 ovaius, Gryphoia vomer, G. mutabiUs, and Ostrea falcafa, are found 

 without a shadow of difference from New Jersc}^ to Louisiana; although 

 some species have been found in the latter State that have not been 

 noticed in the former, and vice versa.''' 



The calcai'eous strata appear to be much less extensively distribut- 

 ed than the friable marls, and present considerable dilference in their 

 organic characters, and always when observed form the overlying beds 

 of this formation. 



Two sections of the strata, as observed in Delaware, are furnished. 

 Localities of exposure are mentioned in Maryland, Virginia, North and 

 South Carolina, Georgia, Alabama, Mississippi, Tennessee, Louisiana, 

 Arkansas, Missouri, and in the level country between the Missouri river 

 and the Rocky Mountains. 



He described: NaiUitns dekayi. Ammonites navicularis, A. pet- 

 echialis, A. telifer, A. conradi, now Scaphites conradi, A. conradi, A'ar. 

 gulosus, now Scaphites conradi, var. gulosus, Scaphites reniformis, A. 

 vespertinus, now Ilortoniceras vespertinum, A, syrtalis, now Placenti- 

 ceras syrtalis, Baculites asper, B. carinatus, B. columna, B. labyrin- 

 thicus, Hamites ar cuius, H. torquatus, H. traheatus, TrocMis leprosus, 

 now Phorus leprosus, Delphinula lapidosa, now Angaria lapidosa. 

 Turritella encrinoides, T, vertehroides, Scalaria sillimani, S. annulata, 

 Rostellaria pennata, JSI atica abyss ina, now Gyrodes abyssina, jSF. 

 petrosa, now G. petrosus. Cirrus crotaloides. Patella tentorium, Ostrea 

 cretacea, 0. plumosa, Pecten craticula, Placuna. scabra^ Inoceramus 

 barahini, 1. alveatus, Avicula laripes, Pectuncultis australis, now 

 Axinoia australis, P. hamula, now A. hamula. Area rostellata, now 

 Cibota rostellata, Cucullcea ardrosa^ now Idonearca antrosa, (J. vul- 



