103 



The discovery of this formation in the far west is a matter of the 

 highest geological interest, and its existence in the Black Hills being 

 now well established, we may look for its discovery in many other 

 parts of the west, and it will undoubtedly be found holding a similar 

 position all along the eastern slope of the Rocky mountains. 



No well marked fossils have yet been obtained from the supposed 

 devonian period in Kansas or Nebraska, and its existence there is, 

 with our present evidence, quite problematical. 



A large collection of fossils was secured from the carboniferous 

 group, in the Black Hills, near the Laramie range of mountains, in 

 the southeastern portion of Nebraska, and in various parts of Kansas. 

 A large and fine collection of carboniferous and permian fossils were 

 collected by Mr. F. B. Meek and the writer, in Kansas, during the 

 past summer. These fossils are now being investigated at the Smith- 

 sonian Institution. I will therefore omit a catalogue of the car- 

 boniferous fossils until our results are more complete. The organic 

 remains from all the localities above mentioned, as well as from many 

 other parts of the west and southwest, have several species in common, 

 and the others are of the same types ; so that the evidence seems to 

 be conclusive that these limestones are all of tlie same geological age, 

 and belong to the true coal measures. 



One of the most interesting series of rocks in the west are best 

 developed in Kansas, but most probably exist near the Black Hills 

 also. These rocks were at first supposed to be the American repre- 

 sentatives of the permian group of Europe ; but much more study 

 will be required to give them their exact position in the geological 

 scale. A large collection of fossils from these rocks has been studied 

 with considerable care by Mr. Meek and the writer, and they seem to 

 warrant the conclusion that by far the greater portion of the strata of 

 the so-called permian in the west hold an intermediate position 

 between the carboniferous and the permian of the Old World. A 

 thorough and clear solution of this problem becomes, therefore, the 

 most interesting feature in American geology at the present time.* 



The following species, most of which are of permian types, have 

 been described by Mr. Meek and the writer, and published in the 

 Transactions of the Albany Institute. The larger part of them were 

 obtained by Mr. Hawn and Dr. Cooper in Kansas, and the remainder 

 were collected by the writer in Nebraska, opposite the northern boun- 

 dary of the State of Missouri, and in the Black Hills, while attached 

 to Lieutenant Warren's party : 



1. Blonotis Haioni ; Meek and Hayden. 



2. Myallna {3Iytilus) perattenuatus ; Meek and Hayden. 



3. Bakevellia parva ; Meek and Hayden. 



4. Edmondia ? Calhouni ; Meek and Hayden. 



5. Fleurophorus f occidentalis ; Meek and Hayden. 



'-"' Tlie upper portion of the so-called permian iu Kansas seems to be destitute of true 

 carboniferous fossils, but contains an abundance of those belonging to permiuu types. 

 We are therefore of the opinion that the upper two or three hundred feet of the*e rocks 

 are probably on a parallel with the permian of Europe, and that the intermediate group 

 which we have mentioned fills up the hiatus between the carboniferous and permian of 

 the Old World. 



