INTRODUCTION. 3 



pressus, Scaphites nodosus, Helicoceras Mortoni, H. tor-turn, H. umhilicatum, Ptycho- 

 ceras Mortoni, Fusus vinculum, Anisomyon borealis, Amauropsis paludiniformis, 

 Dentalium. gracile, Crassatella Evansi, CucuUaea Nehrascensis, Inoceramus sublsevus, 

 I. tenuilineatus, I. Nehrascensis, I. Vanuxemi, boues of Mosasaurus, &c. 

 No. 5. Gray ferruginous and yellowish sandstones and arenaceous clays, 500 feet in thickness. 

 Location : Fox Hills near Moreau River, above Port Pierre near Long Lake, and 

 along the base of Big Horn Mountains. Characteristic fossils are Belemnitella hulhosa. 

 Nautilus Dekayi, Ammotiites placenta, A. lobatus, Scaphites Conradi, S. Nicolleti, 

 Baculites grandis, Busycon Bairdii, Fusus Culbertsoni, bones of Mosasaurus, &c. 



A section of the New Jersey Cretaceous deposits, according to Messrs. Meek and 

 Hayden,' as compiled from tiie observations of Prof Geo. H. Cook, exhibits the 

 following structure : — 



Earlier Cretaceous — 

 No. 1. Dark blue, ash colored and whitish clays and micaceous sand, with thin seams of lignite. 

 Great quantities of sulphuret of iron. Fossil wood in some of the layers in large 

 quantities, and angiospermous leaves. 130 feet or more in thickness. 



Later Cretaceous — 

 No. 4. Dark clays, with occasional streaks and spots of Greefi-sand, containing Ammonites Dela- 

 warensis, A. placenta, Baculites ovatus, etc. 130 feet in thickness. 

 First or lower bed of Green-sand, containing Nautilus Dekayi, Baculites ovatus, Belemni- 

 tella mucronata, Terehratula Sayi, Ostrea larva, Exogyra costata, Gryplixa vesicu- 

 laris, etc. 60 feet in thickness. 

 Quartzose sand, highly ferruginous ; argillaceous in its upper part, containing Belemnitella 

 mucronata, Ostrea larva, Exogyra costata, Neithea Mortoni, etc. From 65 to 70 feet 

 in thickness. 

 No. 5. Second bed of Green-sand. This includes the yellow limestone of Timber Creek, containing 

 Montivaltia Atlantica, Nucleolites crucifer, Ananchytes cinctus, etc. Also a bed of 

 nearly unchanged shells, among which are Terehratula Harlani, Gryphaea lateralis, 

 G. convexa, etc. Lastly, Green-sand, etc., containing Scaphites Gonradi, Baculites 

 ovatus, Ammonites placenta, Gucullsea vulgaris, etc. From 45 to 50 feet in thickness. 



Tertiary — 

 Quartzose sand resembling ordinary beach sand, and destitute of fossils. From 45 to 50 feet in 



thickness. 

 Third, or upper bed of Green-sand. 60 feet in thickness. 



In Alabama, according to Prof. Winchell, as communicated by Messrs. Meek 

 and Hayden,^ the Cretaceous formations are as follows: — 



Earlier Cretaceous — 

 No. 1. Dark blue and mottled shales or clay, with vegetable remains. 300 feet or more in thickness. 



Later Cretaceous — 

 No. 4. Grayish and yellowish sand, with fossil wood and Teredo tibialis; 15 feet. 



Gray sand with Ammonites placenta, A. Delawarensis, Gryphsea vesicularis, Exogyra 



costata, Inoceramus biformis, Pecten quinquecostatus, etc. ; 6 feet. 

 Soft white limestone (" Rotten limestone"), with Nautilus Dekayi, Ammonites Delawarensis, 



Baculites ovatus, etc. ; 150 feet or more. 

 Loose white sand, with Ostrea larva, Pecten quinquecostatus, Gryphsea vomer, etc. ; 45 feet. 



' Proc. Acad. Nat. Sci. 1851, 121 ; 1861, 426. " Ibidem ISSt, 126. 



