INTRODUCTORY. VII 



The scope and plau of the proposed work hiiving been left entirely to 

 my discretion, you may reasonably desire to be informed in advance of 

 its character. To bring the work within the compass of a single vol- 

 ume, and, particularly, to give it a distinctive character apart from the 

 several North American Ornithologies published or in progress,* it 

 seemed necessary to restrict its scope to some particular portion of the 

 West. The Missouri Eegion, in its broadest sense, as embracing the 

 whole water-shed of that great river and its tributaries, was selected in 

 illustration of the "Birds of the Northwest" — both as affording a prac- 

 tically convenient limitation, and as being the scene of most of your 

 ornithological field-work, as well as of some of my own. All the species 

 at present known to inhabit this region (representing a large majority 

 of the birds of North America) are given ; and I have not hesitated, 

 moreover, to introduce certain others, some notice of which seemed 

 desirable to complete an account of particular groups. Three families, 

 namely, Laridce, Coli/mhida', and Podicijndce, which have been with me 

 the subjects of special study, are treated monographically, as far as the 

 North American genera and species are concerned. 



The birds of the ^Missouri Eegion, like most others of North America., 

 having been repeatedly and sufliciently described, text of this tech- 

 nical kind has been omitted as a rule to make room for fresher matter of 

 more general interest. In some cases, however, I describe particular 

 plumages not yet well known, while throughout the monographs above 

 mentioned, descriptions both of external features and anatomical char- 

 acters will be found in detail. For other descriptions I must refer to 

 general treatises. 



The matter of geographical distribution receives the special consider- 

 ation which its importance warrants. Correct indication of habitat is 

 one of the most essential items in the history of a species. The distri- 

 bution of the species, their residence or migration, and their abundance 

 or scarcity, are worked out, not only within the region indicated, but 

 throughout the general area they inhabit. 



The study of these important points having necessarily involved a 

 protracted examination of the general ornithological literature bearing 

 upon this subject, one result of such investigation has been the collation 

 of very extensive synonymatic lists. Nothing like this amount of bib- 

 liographical matter has before been presented in any work upon Amer- 

 ican Ornithology. The synonymy, as simply such, is believed to be very 

 nearly coniplete, while the many thousand additional references furnish 

 an extensive index to the literature of the subject. The labor of such 

 comi)ilation does not appear upon the surface, and is only mentioned in 

 the sincere hope that, once accomplished, the weary drudgery of future 

 workers in the same vein may be materially lightened. The quotations 

 have been personally made or veriiied, in all cases in which this was 



* The alhision is bcrc to tbe niaguiticent general work, in course of ijreparation by 

 Baird, Brewer, iiiul Kiilgway. 



