144 
PROCEEDINGS OF THE ACADEMY OF 
Vertical section of Carboniferous rocks in the Blade Hills. 
2. — Yellow magnesian limestone, rather hard and compact, passing down into 
a somewhat friable arenaceous limestone, underlaid by a bluish limestone, 
very hard, and containing a Productus like P. cora, and a Rhynconella. 
1. — Yellowish gray arenaceous limestone, with a reddish tinge, splitting into 
thin slabs parallel with the lines of stratification ; containing a Spirifer, per- 
haps identical with S. cameratus ; a Productus like P. cora ; corals, a 
Zaphrentis, Syringopora, &c. In the middle of this bed there is an eight 
foot layer of very hard compact bluish limestone, filled with comminuted 
crinoidal remains. 
The lower portion of bed (1) is the same as bed a of the Laramie section, and 
contains fossils at both localities which are similar to Lower Carboniferous 
types, along with some well marked Carboniferous species. In the Black Hills 
it contains a species of Euomphalus, resembling a species common in the 
Encrinital or Burlington limestone of the Lower Carboniferous series of the 
Western States, but perhaps distinct. 
Bed 2 includes beds a and 6, of the Laramie section, bed c being absent iji 
the Black Hills section. 
From the geological position, texture of the rocks, similarity, and in some 
cases identity of species of fossils, I think it quite certain that the limestones 
at Fort Laramie and in the Black Hills are the same as those so well devel- 
oped in the vicinity of Salt Lake, in Utah Territory. 
V. Permian Rocks. 
Although but a short period has elapsed since, through the collections of 
Maj. Hawn, the evidence of the existence of this system of rocks in the West 
has been given to the world, it has already been shown to occur over a wide 
geographical area. In addition to Maj. Hawn's discoveries in northeastern 
Kanzas, which were announced in February last, and the paper published 
March 2d, by Mr. Meek and the writer, Dr. Shumard stated, at a Meeting of 
the Academy of Natural Sciences, at St. Louis, March 8th, that he had been 
studying a group of fossils from a white limestone in the Guadalupe Mountains, 
of New Mexico, and arrived at the conclusion that they were of Permian age. 
He also says, that several of the species are identical with Permian forms from 
England and Russia; also identical with species obtained from the Permian 
rocks in Kanzas. It is now known to occur in a number of localities in the 
central portions of Kanzas also along the Missouri River and opposite the north- 
ern boundary of the State of Missouri, and the evidence is quite conclusive, 
that it is developed in the Black Hills. Many stray masses of compact silicious 
rock were found in and around the Black Hills, containing fossils identical with 
those described from Kanzas. This question has already been discussed in 
a former paper, and I have considered the two beds E and F of the Section as 
Permian, with a query, the evidence not being sufficient to establish its exist- 
ence with certainty. In a letter to the Academy of Sciences at St. Louis, dated 
March 31st, Dr. Norwood announced the discovery of Permian fossils in Illinois, 
and at the Meeting of the American Association for the Advancement of Science 
at Baltimore, Mr. A. H. Worthen, State Geologist of Illinois, read a paper on the 
Permian rocks of that State, and exhibited a fine collection of fossils, which 
he considered as belonging to that system. We have, therefore, reliable evi- 
dence of the existence of these rocks in Kanzas, Nebraska, New Mexico and 
Illinois, and future investigations will, I think, prove them well developed in 
Missouri and other Western States.f 
* I have endeavored to represent this formation on the map, in Kansas, from 
information derived from Major Hawn's explorations. 
fin our remarks of the 2d of March, upon the discovery of supposed 
Permian rocks in the West, both Mr. Meek and myself wish to be understood 
as referring to their existence in Kanzas and Nebraska. Our object being 
simply to announce our conclusions derived from the study of fossils col- 
[JBBC; 
