PREFACE V 



Robert T. Moore, Pasadena, and the late J. H. Fleming, Toronto. The 

 total number of specimens thereby made available for study in the present 

 connection is hard to estimate but runs into many thousands. 



As in Part IX, the author has made extensive use of the manuscript 

 notes left by the late Robert Ridgway. His notes covered the diagnoses 

 of genera and higher groups and partial synonymies for many of the 

 species and subspecies. Wherever possible his manuscript has been in- 

 cluded with the minimum of change (other than addition to synonymies) 

 permitted by more recent data. In fact, it has been, and still is, the 

 present author's feeling that this work should be as largely Ridgway's as 

 possible ; thus, for instance, he has kept and included Ridgway's diagnoses 

 of certain genera now relegated to the position of subgenera, and where 

 Ridgway's manuscript gave extensive synonymies for extralimital forms, 

 he has retained them without attempting to supply equally detailed 

 accounts for other extralimital forms. However, all such manuscript 

 material has been thoroughly studied with the specimens and the litera- 

 ture ; nothing has been accepted merely because it was written. From the 

 start, the author has felt himself responsible for the entire contents of 

 this volume and has not considered himself as an editor of an unpublished 

 work. 



Measurements of specimens for use in the preparation were made by 

 the author and by A. L. O'Leary, Dr. E. M. Hasbrouck, and J. S. Webb 

 under the author's supervision. Maj. Allan Brooks contributed (before 

 the present author began this work) a series of notes on the colors of the 

 unfeathered parts of many of the species discussed herein. The outline 

 drawings of generic details, except those previously published, were made 

 partly by E. R. Kalmbach, and partly, under the author's supervision, by 

 Mrs. Aime Awl, of the United States National Museum staff. 



Herbert Friedmann. 



