102 



distinguished Secretary of that Institution for the numerous facilities 

 he has very kindly afforded for their investigation. 



F. V. HAYDEN, 

 Geologist and Naturalist. 

 Lieutenant G-. K. Warren, 



Topographical Engineers, U. S. A. 



GEOLOGY AND PALEONTOLOGY. 



In order to render this catalogue something more than a mere list 

 of species, I have attempted to present a summary of the geological 

 formations, as far as they are at present known, in Kansas and Ne- 

 braska. This will render more clear the geological relations of the 

 fossils from the Potsdam sandstone to the pliocene tertiary. 



The rocks of Nebraska, as far as they are at present known, are 

 referrible to the following geological systems: 



1. Metamorphosed azoic rocks, including coarse granite. 



2. Lower Silurian. (Potsdam sandstone.) 



3. Devonian. 



4. Carboniferous. 



5. Permian. 



6. Jurassic. 



T. Cretaceous, Upper, Middle and Lower (including Wealden?) 



8. Tertiary. 



9. Post Pliocene or Quaternary. 



Passing over the granitic and azoic rocks, we find that the Potsdam 

 sandstone or the lowest member of the silurian period is quite well 

 developed in the Black Hills. It is there brought to the surface by 

 the upheaval of the igneous rocks and forms a narrow belt around the 

 most elevated portion of the Black Hills. This formation^ though 

 well Icnown and studied in many parts of the United States, had not 

 been discovered in the region of the Rocky mountains prior to Lieu- 

 tenant Warren's exploration of the Black Hills, during the summer 

 of 1857. So far as is yet understood, this member of the geological 

 series has revealed the first indications of organic life on our planet. 

 The following species of fossils,, belonging to what Barrande, the great 

 paleontologist of Bohemia, has called the "Primordial Fauna," have 

 been identified from the Potsdam sandstone of the Black Hills and 

 suitable illustrations prepared. Lingula antiqua, (Hall ;) a species of 

 Lingula very similar to L. prima, .(Conrad,) occurs in vast numbers, 

 forming layers several inches in thickness ; a species of Oholus, very 

 closely allied to 0. oppolinus, as figured by Muchison and De Verneuil 

 in their work on the geology of Russia, and fragments of a trilobite, 

 apparently identical with one of the forms figured by Dr. Owen from 

 the Potsdam sandstone of Minnesota. 



