Po Ey Wa Ca. 
Tue present Memoir, entitled “The Ancient Fauna of Nebraska,” is founded 
upon a large and highly important collection of fossil remains of Mammalia and 
Chelonia, of the Eocene Period, from Nebraska Territory, which have been sub- 
mitted to me for examination by the Smithsonian Institution, Dr. David Dale Owen, 
of New Harmony, Indiana, and Dr. Hiram A. Prout and Prof. O’Loghland, of St. 
Louis, to whom I express my sincere thanks for the interest they have taken in 
my labors. 
To Prof. 8. F. Baird, Dr. S. D. Culbertson, Messrs. Alexander, Joseph, and 
Thaddeus Culbertson, Capt. Stewart Van Vliet, Dr. 8. G. Morton, Dr. John H. B. 
M‘Clellan, Dr. A. H. Senseny, and Mr. J. S. Phillips, I am also obliged for the 
aid which they have contributed to the work. 
I embrace the present occasion to acknowledge the talent of the artists who 
have added so greatly to the value of the Memoir, by the excellent and faithful 
drawings which accompany it, viz.: Mr. A. Sonrel, of Woburn Centre, near Boston, 
and Messrs. A. J. Ibbotson, A. Frey, F. Shell, and I. Butler, of Philadelphia. 
