IXTRODUCTIOX. 



In Classification, Nomenclature, and Xumeration the present -R-ork corre- 

 sponds strictly with the " Cheek List of North American Birds" published by the 

 American Ornithologists' Union,' which represents the joint labors of a " Commit- 

 tee on Classification and Nomenclature" appointed by the Union during its first 

 Congress, held in New York City, September 26-29, 1883. 



During the year which has elapsed since the publication of the A. O. U. Cheek 

 List several species have been added to the North American fauna, while others 

 Lave been for the first time described. These are of course included in the present 

 work, being interpolated in their proper places.* At the same time, it has been 

 considered desirable, in the interest of the student of North American Ornithol- 

 ogy, to include, for reasons stated farther on,' certain extralimital species from 

 contiguous countries. All such additional species have, however, been carefully 

 distinguished typographically, in order that no confusion maj- arise, the method 

 of discrimination being as follows : 



(1) All species which are undoubtedly North American, even though of doubt- 

 ful validity, arc in larger type, those given in the A. O. U. Check List proper being 

 numbered as in that list, while eighteen of the twenty-six species composing the 

 so-called "Hypothetical List,"* and also those subsequently added to the fauna, are 

 preceded by a dash ( — ) instead of a number. (2) All species which have not been 

 established as North American (the majority never having been claimed as such) 

 are pripted in smaller type, and have neither a number nor a dash. 



The Geographical Limits are also, so far as numbered species are concerned, 

 those of the A. O. U. Check List ; but practicallj' these limits have been enlarged so 



' The Code of Nomenclature | and | Check List | of North American Birds | Adopted by the American 

 Ornithologifts' Union | Being the Report of the Committee of the Union on Classification and Nomenclature | 

 (Motto) I I New York | American Ornithologists' Union | 18S6 | [Svo., pp. i-viii, 1-392.] 



' For lists of these additional species, see Appendix, pages S91-59+. 



• Sec ander " Ocographical Limits." 



* " Consisting of species which have been recorded as North American, but whose status as North Ameri- 

 can birds is doubtful, cither from lack of positive evidence of their occurrence within the prescribed limits . . . 

 or from absence of satisfactory proof of their validity as species." Of the twenty-six species constituting this 

 list, eighteen arc unquestionably North American (one of them having been recently established as such), while 

 the remaining eight have very scant claims to a place in oar fauna. 



