14 Cincinnati Society of Natur.al History. 



greensand region, this bed is in the condition of a loose sand, but 

 abounds in organic remains in the state of solid casts. 



Fifth. — Resting npon the former, and constituting the highest as- 

 certained member of the Cretaceous series in the State, there occurs a 

 coarse, brown ferruginous sandstone, sometimes passing into a con- 

 glomerate. It is composed of translucent quartzose sand, small frag- 

 ments of felspar, and pebbles of white quartz, cemented together by a 

 dark brown paste of oxide of iron. The green mineral in detached 

 grains is likewise a common ingredient. The position of this rock is 

 usuall.y upon the summits of the insulated outlying hills, which rise 

 occasionally above the general plain of the marl region. 



This division into beds is merely descriptive of the local appearance 

 of the Cretaceous of New Jerse}^, and has never been regarded as of 

 an}^ service in the separation of the Cretaceous, in other States, into 

 groups, nor has it been retained in New Jerse}', since the geologists 

 have been able to separate the strata by their organic remains. 



In 1841, James C. Booth, in his Memoir of the Geological Survey of 

 Delaware, divided the Cretaceous of that State, which is found super- 

 imposed upon the primarj^ rocks, and extends from the lower limit of 

 the primary nearlj^ to the southern border of New Castle count}^, into 

 red cla3^, and green and yellow sands. He estimated the thickness at 

 not less than 330 feet. 



In this 3"ear, Prof. J. W. Bailey* discovered that a large part of the 

 calcareous green sand of New Jersey, the limestone from Claiborne, 

 Alabama, and a light cream-colored marl fj'om a mission station on 

 the Upper Mississippi, called " Prairie Chalk," is composed of micro- 

 scopic shells belonging to the foraminifera. 



In 1842, Dr. Morton f described, from the Cretaceous of the upper 

 Missouri river. Ammonites mandanensis, A. ahyssinus and A. nicol- 

 letti, all of which are now referred to the genus Scaphites, and to the 

 Fox Hills Group ; Hipponyx horealis^ now Anisomyon horealis, 

 Cytherea missuriana^ now Dione missnriana and Tellina occiden- 

 talism now Liicina occidentalis. And from the Cretaceous group, of 

 New Jerse}', Ammonceratites conradi, now Crioceras conradi, Ham- 

 ites annulifer, now Ftychoceras annuliferum..^ Pinna rostriformis., 

 Terehratula atlantica^ Planularia cuneata, Cidarites armiger. And 

 Ptycodus mortoni, by Mantell, from the Cretaceous, at Prairie Bluff, 

 Alabama. Dr. James E. Dekay, des(;ribed,J; from the Cretaceous 



=■■ Am. Jour. S;!. and Arts, vol- 41. 

 t Jour. Acad. Nat. Sci., vol. 8, part 2. 

 \ Zool- of New York. 



