Office of the U. S. Geological Exploration 



OF THE Fortieth Parallel, 



Neiv York, April, 1877. 



General: Herewith I have the honor to transmit Vohune IV of the 

 Reports of this Exploration, composed of Memoirs on Palaeontology, by 

 Messrs. F. B. Meek, James Hall and P. P. "Whitfield; also on Ornithology, 

 by Robert Ridgway. 



Very respectfully, your obedient sei'vant, 



CLARENCE KING, 



Geologist-in-cJiargc. 



Brig. Gen. A. A. Humphrey.s, 



Chief of Engineers U. S. Army, 



Washington, D. C. 



XI-XII 



