PREFATORY NOTE TO PART III. 
The information collected by the expedition in the department of natural history is embodied 
in this part of the report. It is proper to state that much of the credit for whatever of value 
the papers may contain is due to the Smithsonian Institution. Professor Henry, the secretary, 
has afforded every assistance in his power to the expedition, in the way of office rooms, of free 
access to the library, and to the natural history collections of the institution, and of the time 
and personal assistance of its officers. The instructions of the zoological collectors; the classi¬ 
fication of the materials collected; and the elaboration of their scientific descriptions and names, 
are all the work of Professor Baird, the assistant secretary, and of his immediate assistants. 
This gentlemen has also attended to the proper selection of subjects for illustration, and to the 
proper expenditure of the money set apart by me for this purpose. The engravings have been 
made by competent artists within the walls of the institution, and their excellence is the 
guarantor of the personal attention and interest of Professor Baird. 
The collectors of the party, Dr. Suckley and Dr. Cooper, have availed themselves of every 
opportunity to enhance the value of the collection, both while in the field and subsequently 
while residing in the west. They have also devoted much time to comparing and arranging the 
materials collected, and to adding to Professor Baird’s scientific descriptions many interesting 
notes upon the habits and peculiarities of the different species. These notes will be found in 
the several sub-reports prepared, with the exceptions above mentioned, by these two gentlemen, 
and herewith presented. 
ISAAC I. STEVENS. 
