X BULLETIN 17 9, UNITED STATE'S NATIONAL MUSiEUM 



The plumages are described in only enough detail to enable the 

 reader to trace the sequence of molts and plumages from birth to 

 maturity and to recognize the birds in the different stages and at the 

 different seasons. 



No attempt has been made to describe fully the adult plumages; 

 this has been well done already in the many manuals and State books. 

 Partial or complete albinism is liable to occur in almost any species ; 

 for this reason, and because it is practically impossible to locate all 

 such cases, it has seemed best not to attempt to treat this subject at 

 all. The names of colors, when in quotation marks, are taken from 

 Ridgway's Color Standards and Nomenclature (1912). In the meas- 

 urements of eggs, the four extremes are printed in bold-face type. 



Many who have contributed material for previous volumes have 

 continued to cooperate. Receipt of material from over 475 contribu- 

 tors has been acknowledged previously. In addition to these, our 

 thanks are due to the following new contributors: "VV. L. Bailey, H. 

 Brackbill, F. G. Brandenburg, I. McT. Cowan, W. V. Crich, J. R. 

 Cruttenden, L. I. Davis, J. D. Daynes, D. Grice, E. N. Harrison, 

 H. L. Heaton, T. A. Imhof, C. Kinzel, Mrs. F. C. Laskey, Miss 

 Katherine Merry, E. F. Porter, P. Steib, W. E. Unglish, and Univer- 

 sity of Colorado Libraries. If any contributor fails to find his or her 

 name in this or some previous bulletin, the author would be glad to be 

 advised. As the demand for these volumes is much greater than the 

 supply, the names of those who have not contributed to the work dur- 

 ing the previous 10 years will be dropped from the author's mailing list. 



Dr. Winsor M. Tyler rendered valuable assistance by reading and 

 indexing, for these groups, a large part of the literature on North 

 American birds, and contributed four complete life histories. Dr. 

 Alfred O. Gross and Alexander Sprunt, Jr., contributed two each; 

 and Bayard H. Christy, Edward von S. Dingle, Rev. F. C. R. 

 Jourdain, Dr. Gayle Pickwell, and Robert S. Woods contributed one 

 each. 



Egg measurements were furnished especially for this volume by 

 American Museum of Natural History (Dean Amadou), Griffing 

 Bancroft, Colorado Museum of Natural History (F. G. Branden- 

 burg), California Academy of Sciences (James Moffitt), F. R. Decker, 

 C. E. Doe, J. B. Dixon, Field Museum of Natural History (R. M. 

 Barnes collection), J. H. Gillin, W. C. Hanna, H. L. Harllee, T. E. 

 McMullen, Museum of Comparative Zoology (J. C. Greenway), 

 Museum of Vertebi-ate Zoology (Margaret W. Wythe), J. S. Rowley, 

 G. H. Stuart, 3d, and the United States National Museum (J. H. 

 Riley). 



Our thanks are due also to F. Seymour Hersey for adding and 

 figuring the egg measurements, and to W. George F. Harris for sort- 



