2 ON THE GEOLOGY AND NATURAL HISTORY 
and though they appear to have had no definite idea of the geological age of the region 
examined by them, they gave so accurate descriptions of the general physical features of 
the bluffs, coal-beds, &c., that their report has proved an excellent guide to subsequent ex- 
plorers. They often mention beds of “stone coal” (lignite), different strata of sands, sand- 
stones, clays, &c., yet do not suggest any idea of the age of these deposits. A small 
collection of cretaceous fossils obtained by these travellers enabled Dr. Morton* to identify 
the existence of the Cretaceous formation in that country. 
In 1832, the Prince of Neuwied made an expedition up the Missouri river, and the re- 
sults of his travels were embodied in a magnificently illustrated work. The sketches taken 
from nature present a very vivid and accurate idea of the country. He mentions the oc- 
currence, in numerous localities, of sands, clays, and lignites, and also observes that he 
collected Ammonites, Baculites, and other Cretaceous fossils, all along the river from the 
sources of the Missouri to Big Sioux. This statement led Von Buch to observe that 
“this great river (Missouri) flows uninterruptedly from the foot of the Rocky Mountains 
through strata of Chalk, at least as far as the mouth of Sioux river. ‘This is the result of 
the accounts and collections of Prince Neuwied and of the report of the celebrated astro- 
nomer Nicollet.”+ Nothing very definite was ascertained however respecting the geology 
of the country by this expedition, except to confirm the fact of the existence of a Creta- 
ceous formation on the Upper Missouri, indications of which had already been determined 
from the collections of Lewis and Clarke. He also obtained a fine specimen of the remains 
of a saurian animal, characterizing the Cretaceous Period, which has been described by 
Goldfuss as Mosasaurus Maximiliani, fragments of which were in the collections of Lewis 
and Clarke. 
The next important expedition into that country was made in 1839, by the distinguished 
geographer Nicollet. He ascended the Missouri no farther than Fort Pierre in lat, 44° 
23’, yet from his observations the first reliable information was obtained respecting the 
extent and interest of the Cretaceous rocks in that region. 
He secured a considerable number of Cretaceous fossils at different points along the 
Missouri, but especially at the Great Bend; all of which were described by Conrad and 
Morton in the Proceedings of the Philadelphia Academy. Although passing rapidly 
through the country he formed a tolerably accurate idea of its geology, and gave in his re- 
port a vertical section of the Cretaceous rocks, which is correct, excepting that he seems to 
have had no knowledge of No. 2, and represented two of the subdivisions of No. 3 as dis- 
* Synopsis of the Organic Remains of the Cretaceous Groups of the United States, &c., by S.@. Morton. Phila- 
delphia, 1834. 
+ Silliman’s Journal. September, 1850. 
