U. S. GEOGRAPHICAL AND GEOLOGICAL SURVEY OP THE ROCKY MOL\T\L\ REGION. 



J. W. FOWELL, IN CHARGKE. 



PRELIMINARY REPORT 



OX THE 



PALEONTOLOGY OF THE BLACK HILLS, 



K. P. WHITFIELD, 



CONTAINING DESCRIPTIONS OF NEW SPECIES OF FOSSILS FROM THE 



POTSDAM, JURASSIC, AND CRETACEOUS FORMATIONS | 



OF THE BLACK HILLS OF DAKOTA. 



WASHINGTON: 



GOVERNMENT PRINTING OFFICE. 

 July, T877. 



