PREFACE TO THE SECOND EDITION. 
Durine the eight years which have passed since the first edition 
of this work was published the number of active ornithologists in the 
United States has greatly increased, and through their united research 
in the exploration of new or imperfectly worked fields and the careful 
revision of particular genera our knowledge of North American birds 
has been materially extended, thus rendering a new and carefully 
revised edition extremely desirable. It is well known that few, if any, 
books are quite free from typographical and other errors, due to various 
exigencies, avoidable and otherwise. Such imperfections of the first 
edition have been located, largely by friends and correspondents who 
have detected them in their practical use of the book, and have all, 
so far as they have been discovered, been corrected. 
Of the ninety-one species and subspecies which have been added 
to the North American fauna since 1887, twelve were fortunately 
included in the analytical “keys,” and it has therefore been necessary 
in their case only to change the typography of the names and prefix 
the catalogue number of the AmERIcAN Ornituoxogists’ Union’s 
“Check List of North American Birds.” The remainder are given in 
regular order in the Appendix (pages 583-614), marginal reference 
numbers in the body of the work at once directing attention to the 
supplementary matter. 
Some complaint has been made that in the original edition no 
directions were given for using the “keys.” This omission was not an 
oversight, such directions being deemed unnecessary because it was 
supposed the plan of the keys was so simple as to be self-explanatory. 
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