PREFATORY NOTE TO PART TV. 



The information collected by the expedition in the department of Natural History is 

 embodied in this portion of the Keport. 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 

 Kange. 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. 



