Philadelphia, January 13, 1873. 

 Dear Sir: Herewith I transmit to you my report on vertebrate fossils from 

 the Western Territories and States. Many of the specimens were collected 

 during your geological explorations, and were submitted to me for investiga- 

 tion. Others have been collected by different persons living in the West, 

 and sent to me directly, or through the agency of the Smithsonian Institution, 

 for examination. Most of the fossils were obtained in Wyoming, and the 

 others were derived from Oregon, California, New Mexico, Idaho, Colorado, 

 Kansas, and Nebraska. 



With respect, I remain, at your service, 



JOSEPH LEIDY. 

 Professor F. V. Hayden, 



United States Geologist. 



2 G 



