Equivalent of Nos.111,1 _ 



C and D of Ni- 



IV, V, and VI of the i „ , 



collet s section. 



New Jersey section. J 



130 GEOLOGY AND PALEONTOLOGY. 



Owen, has collected, and with Dr. B. F. Shumard, has described, several new cretaceous species 

 from the same region.. 



In 1853, Messrs. F. B. Meek and F. V. Hayden made an extensive collection of the fossils of 

 the cretaceous formation upon the Missouri river in Nebraska ; and among these somewhat more 

 than thirty new species, a number equal to all the cretaceous species before known as occurring 

 in that region. These species were described by the writer, in connexion with Mr. Meek, in 

 the Memoirs of the American Academy of Arts and Sciences.* A section of the cretaceous and 

 tertiary strata of the Missouri river and the Mauvaises Terres, compiled from the notes of Mr. 

 Meek, made upon the ground and verified by subsequent examination of the fossils, likewise 

 accompanied the paper just noticed, on page 405 of the same volume. 



The order of succession among the beds constituting the cretaceous formation, and their litho- 

 logical character there established, are as follows : 



Section of the members of the cretaceous formation, as observed on the Missouri and thence loest- 

 tvard, including the tertiary beds of the Mauvaises Terres. 



Tertiary formation Indurated clays, beds of sandstone, conglomerate, limestone, &c., contain- 



ing remains of Mammalia and Chelonia, with a few species of fresh water 

 shells. 

 V. — Arenaceous clay, passing into argillo- calcareous sandstone ; 80 feet 



thick. 

 IV.— Plastic clay, with cilcareous concretions, containing numerous fossils ; 

 950 to 300 feet thick. (This is the principal fossiliferous bed of the cre- 

 taceous formation upon the upper Missouri.) 

 !III. — Calcareous marl, containing Ostrea congesia, Inoceranms problematicus,^ 

 scales of fishes, Stc.; 100 to 150 feet thick. 

 11. — Clay containing few fossils ; 80 feet thick. 



I. — Sandstone «nd clay; 90 feet. The probable equivalent of Nos. I and II 

 of the New Jersey section. 



Carboniferous formation I. — The sandstone. No. I of section, rests upon buff colored magnesian lime- 



stone'of the upper carboniferous period. 



In this section Nos. II and III correspond to A and B of Mr. Nicollet's section, while the 

 sandstone, No. I, was either overlooked by him, or may have been referred to the carboniferous 

 strata. I 



The divisions C and D of Mr. Nicollet's sections are subdivisions of Nos. IV and V of our 

 section, or probably of No. IV alone, since No. V is not known to occur on that part of the 



* " Description of New Species of Fossils from the Cretaceous Formation, by James Hall and F. B. Meek. Memoirs of the 

 American Academy of Arts and Sciences, vol. V, new series. 



t In a subsequent exploration of this rei/ion Dr. Hayden discovered Inoceramus ■prohlematini.s in this bed, in precisely the same 

 conditions and in a rock identical with that in which the specimens occur brought by Captain Fremont from the Smoky Hill 

 river, and by Captain Stansbury from between the Big and Little Blue rivers. 



A careful comparison of Inoceramus fragilU, from bed No. 3, Nebraska section, (Hall and Meek, Memoirs Amer. Acad., vol. 

 V, new series, page 388,) has satisfied both Mr. Meek and myself that it is identical with /. problematicus, the specimen described 

 being tlie young of that species. The young specimens of the latter shell from Arkansas and Smoky Hill river present no 

 essential differences from those of Nebraska. 



Dr. Hayden has likewise made extensive collections in other parts of the Nebraska cretaceous and tertiary formations during 

 the past two years. The new species of tliese collections have been described by Messrs. Meek and Hayden, in several papers 

 published in the proceedings of the Academy of Natural Sciences of Philadelphia. These explorations, with the exiensive col- 

 lections of fossils, have served to sustain the correctness of the order of succession anions the subordinate members of the series 

 as given in the section above ; indicating, however, that the beds Nos. II and III, as well as Nos. IV and V, may in some 

 localities merge into each other; while the limits between Nos. ill and IV remain well marked throughout the region explored. 



I From the fact that Mr. Nicollet remarks, (page 35,) that the part of stratum A above water, on the day of his " examina- 

 tion, was three feet," we may infer that the sandstone No. I was not seen by him. 



