Allen, The A. O. U. Check-List. 



TAuk 

 Ljan. 



The present Congress being the twentieth anniversary of the 

 appointment of the ' Committee on the Classification and Nomen- 

 clature of North American Birds,' this seems an opportune occa- 

 sion to review briefly the history of its work, noting statistically 

 the number of changes that have been made in the nomenclature 

 of the Check-List, and the number of additions made to it; and 

 also to attempt to forecast in the light of the past, its prospective 

 modifications. 



First as to the past, which may be considered under the two 

 heads of (i) Additions, and (2) Changes in Nomenclature, noting 

 in each case their nature and number. 



1. Auditions. 



Subfamilies .......... 3. 



Genera 7- 



Subgenera 3. 



Species .......... 54. 



Subspecies . . iSi. 



II. Changes of Nomenclature. 



Family names changed 

 Generic names changed 

 Subgenera raised to genera 

 Total changes in generic names 

 Subgeneric names clianged 

 Specific names changed 

 Subspecific names changed . 

 Binomials chantred to trinomial- 



26. 

 18. 

 44. 



2. 

 38. 



The numerous additions to the Check-List denote the progress of 

 our knowledge of North American ornithology during the last 

 sixteen years, as regards the constituents of the North American 

 avifauna, the increase representing a total addition of 235 species 

 and subspecies and 7 genera. This is a net increase of 24.7 per- 

 cent, or nearly two percent a year. 



' These relate mainly to forms found along our Mexican border which were 

 originally entered as species, Tjut have since been separated from the more 

 southern type form as subspecies. While this effects a change in nomencla- 

 ture, these changes neither add nor subtract any form from the Check-List. 



