VI INTRODUCTION 



different seasons. No attempt has been made to fully describe adult 

 plumages; this has been already well done in the many manuals. 

 The names of colors, when in quotation marks, are taken from Ridg- 

 way's Color Standards and Nomenclature (1912) and the terms used 

 to describe the shapes of eggs are taken from his Nomenclature of 

 Colors (1886 edition). The heavy-faced type in the measurements 

 of eggs indicate the four extremes of measurements. 



Many of those who contributed material for former volumes have 

 rendered a similiar service in this case; In addition to those whose 

 contributions have been acknowledged previously, our thanks are 

 due to the following new contributors: Photographs, notes, or data 

 have been contributed by Griffing Bancroft, C. T. Barnes, O. E. 

 Baynard, R. H. Beck, Hii-am Bingham, C. L. Broley, A. R. Cahn, B. R. 

 Chamberlain, B. H. Christy, J. H. Connery, A. H. Cordier, William 

 Dodd, Eastman Kodak Company, J. M. Edson, W. G. Fargo, W. H. 

 Fisher, I. N. Gabrielson, D. S. Gage, E. W. Hadeler, R. B. Harding, Paul 

 Harrington, C. G. Harrold,R. W. Hendee, H. M. Holland, E. G. Holt, 

 J. S. Huxley, E. R. P. Janvrin, Antonin Jay, G. A. Langelier, J. E. 

 Law, A. G. Lawerence, A. A. V. P. Lechner, R. J. Longstreet, J. B. 

 May, Dan McCowan, H. T. Middleton, N. D. Moser, J. E. Patterson 

 R. B. Ramp, T. E. RandaU, F. W. Rapp, Russell Reid, C. C. Sanborn, 

 E. T. Seton, G. F. Simmons, Alexander Sprunt, F. A. E. Starr, O. A. 

 Stevens, H. S. Swarth, L. W. Turrell, and R. L. Walp. 



Receipt of material from over 200 contributors has been acknowl- 

 edged in previous volumes. 



Through the courtesy of the Biological Survey, the services of 

 Frederick C. Lincoln were secured -to compile the distribution para- 

 graphs. With the matchless reference files of the Biological Survey 

 at his disposal and with some advice and help from Dr. Harry C. 

 Oberholser, his many hours of careful and thorough work have pro- 

 duced results far more satisfactory than could have been attained by 

 the author, who claims no credit and assumes no responsibility for 

 this part of the work. The few minor changes made in the system 

 do not materially alter the general plan. 



F. Seymour Hersey has handled the egg measurements and the egg 

 dates very satisfactorily; both of these involved collecting and work- 

 ing over a great mass of details, involving long hours of tedious 

 work which he volunteered to do. 



Dr. Charles W. Townsend has written the life histories of five 

 species. Rev. P. B. Peabody furnished a generous supply of notes 

 and photographs regarding the yellow rail. A notable contribution 

 has been made by Thomas E. Ponard, who compiled and wrote the 



