INTRODUCTION. 



IN 1873, shortly after the publication of the author's " Key to North American 

 Birds," appeared the original edition of this " Check List," which was almost imme- 

 diately reissued in connection with the same writer's " Field Ornithology," in 1874. 

 That list reflected the classification and nomenclature of the "Key" with much 

 exactitude, although it included, in an Appendix, a few species additional to those 

 described in the "Key," and made some slight changes in the names. Excepting 

 some little comment in foot-notes and in the Appendix, the original " Check List" 

 was a bare catalogue of scientific and vernacular names, printed in thick type on one 

 side of the paper. 



Meanwhile, the science of Ornithology has progressed, and our knowledge of 

 North American birds has increased, both in extent and in precision, until the orig- 

 inal list, faithful as it was at the time, fails now to answer the purpose of adequately 

 reflecting the degree of perfection to which the subject has been brought. A new 

 edition has therefore become necessary. 



The list has been revised with the utmost care. The gratif} r ing degree of accu- 

 racy with which it represented our knowledge of 1873 is exhibited in the fact, that 

 it is found necessary to remove no more than ten names. On the other hand, 

 the progress of investigation has resulted in adding one hundred and twenty names 

 to the list, and in showing the necessity or expedienc}^ of making many changes 

 in nomenclature. The exact analysis of the differences between the two lists is 

 given beyond. 



In revising the list for the main purpose of determining the ornithological statiis 

 of every North American bird, the most scrupulous attention has been paid to 

 the matter of nomenclature, not only as a part of scientific classification, deter- 

 mining the technical relations of genera, species, and varieties to each other, but 

 also as involved in writing and speaking the names of birds correctly. The more 

 closely this matter was scrutinized, the more evidences of inconsistency, negligence, 



