PEEFATOEY NOTE 



U. S. GEOLOGICAL AND GEOGRAPHICAL 



SURVEY OF THE TERRITORIES, 



Washington, D. 0., November 1, 1878. 



RESULTS of Dr. Coues's continued studies of North Ameri- 

 can ornithology, in connection with the Survey under 

 my charge, are herewith presented as one of the series of Miscel- 

 laneous Publications (No. 11). Should circumstances favor the 

 completion of the work, upon which the author is still engaged 

 and which is already not far from finished, the remaining portion 

 may be expected. The present treatise may be regarded as com- 

 plementary to the "Birds of the Northwest" (Misc. Pub. No. 3). 

 It covers much ground not gone over in the latter work, in all 

 that relates to the technicalities of the general subject, as well 

 as to the particular life-histories of the birds composing the 

 remarkable avian fauna of the Colorado Basin. As originally 

 projected for publication in a different connection, the work 

 consisted merely of a report upon the peculiar features of bird- 

 life in the area under consideration, with biographies of the 

 species not treated in the "Birds of the Northwest". But the 

 author's resources have proved to be so largely in excess of the 

 requirements of such a report that the work has outgrown the 

 limits of a single volume, and become a full exposition of our 

 present knowledge of the subject, by the incorporation of much 

 technical matter concerning North American ornithology at 

 large, hitherto the private possession of the author and now 

 first made accessible to the public. 



The whole subject of the bibliography of North American 

 ornithology, and of the synonymy of North American birds, 

 has been worked up anew from the very bottom, as a matter of 

 original personal investigation admitting of nothing at second- 

 hand. Not only the birds of the Colorado Valley, but also all 

 others of North America, are thus exhaustively treated, their 

 synonymy and bibliography being at length placed upon a 

 satisfactory basis. In points of accuracy, completeness and 

 thorough reliability it is believed that this side of the work 



