36 The Wilson Bulletin.— No. 42. 



of 1903. The reason for the imusuual delay in its publication may- 

 be briefly stated. When iDr. Cones died in 1899 he left the manu- 

 script wholly finished, but the copy was rendered hard to decipher 

 without the exercise of most intelligent care by reason of innumer- 

 able interlineations, erasures, abbreviations, "riders," and de- 

 tached notes, written in a minute and sometimes difficult handwrit- 

 ing. It was evident that had the Doctor lived he would have cast 

 his material, although entirely complete as he left it, into a form 

 which would present fewer difficulties to tiie compositor. His sud- 

 den death left the copy in such shape that the task of revision and 

 preparation for the press required double the amount of work 

 that had been anticipated. The publishers, however, have had the 

 good fortune to obtain the services of a thoroughly equipped orni- 

 thologist, who has read the proof with the most painstaking care, 

 which has l)een ably supplemented by the efforts of a number of 

 professional proof readers. The result is a book which Dr. Cones 

 would have been proud to own as the crowning work of his life. 

 The publishers announce it as being absolutely authoritative and 

 definite, and express confidence that it is entirely free from 

 errors of statement or form. 



Some of the features which will make the work more than ever 

 indispensable to ornithologists, professional as well as amateur, 

 may be briefly summarized: 



1. The detailed, careful, descriptions of species — as in former 

 Keys. 



2. The accounts, much fuller than in former editions, of the 

 breeding habits of birds — dates, nests, and particularly the detailed 

 description of eggs, with careful measurements of same. 



3. The full collation in the text (not an appendix as in former 

 editions) of the nomenclature of species in the Key, with the 

 nomenclature and numeration of the American Ornithologists' 

 Union Check List (of especial help to students). 



4. The full synonymies and bibliographical references in the 

 case of nearly all species — a new feature of the Key, and invaluable 

 to students of all degrees of advancement. To the preparation of 

 this important feature of the last edition of his Key, Dr. Coues 

 brought his rare gifts as bibliographer and nomenclator. The 

 amount and painstaking character of this work makes it possible 

 for the student to extend with ease his researches in the case of 

 a great many species. 



5. The professional discussion of questions of classification and 

 nomenclature by perhaps the most eminent of modern ornithol- 

 ogists. 



6. The introductory (i.e., general) descriptions of ordinal, fam- 

 ily, and other groups, are much amplified over those in preceding 

 editions of the Key, being of a broader scope, which make plain 

 the comparative relationships of North American families, genera, 



