PREFATORY NOTE TO PART TV. 
Tiie information collected by the expedition in the department of Natural History is 
embodied in this portion of the Report. It is proper to state that the credit for whatever of 
value the papers may contain is due, in a great measure, to the Smithsonian Institution. 
The outfit and instructions of the zoologist were prepared, and the specimens themselves 
arranged and preserved by this Institution. Under its supervision and within its walls the 
necessary illustrations have been executed, the determination of species made, and the reports 
themselves revised for publication. 
The zoologist of the expedition, Dr. E. Sterling, of Cleveland, Ohio, dissolved his connection 
with the party on reaching Fort Dalles, in consequence of ill health. Subsequent to that time 
the duties of zoological collector were chiefly performed by Dr. J. S. Newberry. The latter gen¬ 
tleman left the party soon after Dr. Sterling, and returned, by water, from Oregon to San 
Francisco. In consequence of his absence and of the Indian disturbances on the route, a 
comparatively small zoological collection was made in the region traversed west of the Cascade 
Range. Mr. C. D. Anderson, however, secured and preserved several valuable specimens on 
this portion of our line of survey. While waiting for the arrival of the party, Dr. Newberry 
zealously occupied himself in making a valuable and extensive collection in the markets and 
the vicinity of San Francisco. 
The expedition is also largely indebted to Lieutenant W. P. Trowbridge, Corps of Engineers, 
and to other gentlemen who have taken advantage of a long residence in the west to collect 
and preserve zoological specimens. Their contributions have been transported to Washington, 
deposited in the Smithsonian Institution, and described in the following reports with those 
made by the collectors of the party. 
HENRY L. ABBOT, 
Lieut. Corps of Top. Engineers. 
