20 INTRODUCTORY LETTER. 



desired, and to their courtesy and uniform kindness much of the success of 

 the natural history operations is attributable. 



In the special work of preparing the reports relative to its collections, 

 the expedition is under obligations to a number of distinguished scientists 

 for their kind and gratuitous services in the Avork of identification of the 

 individual specimens. The following are among the large number of the 

 gentlemen in question: 



In the determination of — 



Mammals, thanks are due to Prof. S. F. Baird, of the Smithsonian Insti- 

 tution; Prof. Harrison Allen, of the University of Pennsylvania; Dr. Elliott 

 Cones, U. S. A., naturalist of the Northern Boundary Survey; Prof. J. A. 

 Allen, of the Museum of Comparative Zoology, Cambridge. 



* ***** * 



I have the honor to be, very respectfully, your obedient servant, 



H. C. Yarrow, 

 Acting Assistant Surgeon United States Army. 

 First Lieut. George M. Wheeler, 



Corps of Engineers United States Army, in charge. 



