INTRODUCTORY. 



\_Dr. Coues to Dr. Hay den.'] 



Fort Kandall, Dakota, 31ay 13, 1873. 



Sir : Herewith I transmit, in compliance with your request, for pub- 

 leation under the auspices of the Geological Survey of the Territories, 

 a Work on the Ornithology of the Missouri Region, on which, as you are 

 aware, I have been long engaged, its completion having been delayed 

 by various circumstances needless to detail. In this connection, how- 

 ever, I may refer to the circumstances under which the work originated, 

 in explanation of its present plan and scope. This is a matter with 

 which you are yourself already familiar, but one which may be presented 

 to answer the purposes of a preface which would otherwise be required. 



The basis of the present volume is mainly an unpublished re])ort 

 which I prepared at Washington, in the year 1862, ui)on the ornitholo- 

 gical collections made by yourself and Mr. G. H. Trook as Naturalists 

 of the Expedition under Captain (now General) W. F. Eaynolds, United 

 States Engineers. The specimens submitted to me for elaboration were 

 subjected to careful examination, and found to represent a decided ad- 

 vance in the knowledge then possessed of the geographical distribution 

 of the species in the region under consideration. The interest attaching 

 to this series of specimens, as an element in the history of Western Or- 

 nithology, renders it advisable, in my judgment, to preserve throughout 

 the present volume the "List of Specimens" which were formally tab- 

 ulated* for the original report. 



In 1807, while stationed at Columbia, South Carolina, I desired to 

 recall my MSS. in order to retouch them according to the steady advance 

 of our knowledge of the subject during the intervening five years. On 

 this occasion it seemed advisable to extend the article to embrace the 

 ornithological results which you had obtained as Naturalist of the j^revi- 

 ous I'Lxplorations, conducted in 1850-57 in the region of the Upper 

 Missouri, Yellowstone, and Flatte Rivers, by Lieutenant (now General) 

 G. K. Warren, United States Engineers. Such addition would not only 



* lu these tables, the first columu gives tlie number which the specimen bears on the 

 register of the National Mnseum at Washington ; the second, the "original" or collect- 

 or's number; third, the locality ; fourth, sex ; Jlfth and sixth, date of collection, and by 

 "whom collected ; scvrnfh, eighth, ninth, measurements (upon collector's authority) of, 

 respect ivi'ly, total ]<Migtli, extent of wings, and lengtii of wing from carpus to apex of 

 longest primary. To economize space, these several headings have been omitted from 

 the text, with explanation in this place, which will prevent misunderstanding. 



