INTRODUCTION XI 



Our thanks are also due to William George F. Harris for many hours 

 of careful work in collecting and figuring the egg measurements and 

 for handling and arranging the vast amount of data used in making 

 up the paragraphs on egg dates. Dr. Eugene E. Murphey did consider- 

 able work on one species, and Stephen Waldron helped with typewriting. 

 Through the courtesy of the Fish and Wildlife Service the services of 

 Frederick C. Lincoln were again obtained to compile the distribution 

 and migration paragraphs. The author claims no credit and assumes no 

 responsibility for this part of the work. 



The manuscript for this Bulletin was completed in August 1941. 

 Contributions received since then will be acknowledged later. Because 

 of the war, publication was delayed, and in September 1945 the author 

 recalled the manuscript to bring it up to date although only information 

 of great importance could be added. The reader is reminded again 

 that this is a cooperative work ; if he fails to find in these volumes any- 

 thing that he knows about the birds, he can blame himself for not having 

 sent the information to — 



The Author. 



