38 ON THE GEOLOGY AND NATURAL HISTORY 
The diagram showing the order of the superposition of the different rocks would apply 
equally well to the similar beds in the Black hills.” Many other less evident indications 
of its existence along the base of the Rocky mountains might be cited from published re- 
ports, but what has been said will be sufficient to show, what we may hereafter expect 
with regard to its geographical distribution in the far West. 
Hitherto no indications of the existence of any other member of the Silurian period 
has been discovered along the eastern slope of the Rocky mountains within the territory 
of the United States. 
CHAPTER IX. 
IT. anv IV. CarBonirrerous AND PERMIAN PERIODS. | 
In a former paper I gave to the Permian rocks of Kansas the position of a distinct 
system in the Kansas and Nebraska series. Subsequent examinations have rendered it 
somewhat questionable whether they are entitled to the rank of an independent system as 
developed in Kansas, but rather should be considered as a continuation upward of the 
Carboniferous period, For this reason I have concluded to treat both subjects under one 
head. In the first place I will give a brief history of the discovery of rocks in the West 
containing fossils belonging to Permian types and supposed to be on a parallel with the 
Permian beds of Europe. ‘The discoveries of Mr. Hawn in Northeastern Kansas were 
announced in February, 1858, in a paper read before the Academy of Sciences at St. Louis, 
in which a number of new species of fossils were described and others considered as identical 
with forms characterizing the Permian rocks of Europe. March 2d of the same year a 
paper entitled, “ Descriptions of new organic remains from Northeastern Kansas, indicating 
the existence of Permian rocks in that Territory,” was read before the Albany Institute, by 
F. B. Meek and the writer; in which were described ten new species of fossils, most of 
which seemed to belong to true Permian types. At a meeting of the Academy of Sciences 
at St. Louis, March 8th, Dr. Shumard stated 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 are of Permian age. He says that several of the species are identical 
with Permian forms from England and Russia, also with species obtained from the Per- 
mian rocks in Kansas. In a letter to the Academy of Sciences at St. Louis, dated March 
31st, Dr. Norwood announced the discovery of Permian fossils in Ilinois; and at the 
meeting of the American Association for the Advancement of Science at Baltimore, in 
April, Mr. A. H. Worthen, State Geologist of Illinois, read a paper on the Permian rocks 
