SEVENTEENTH SUPPLEMENT TO THE AMERICAN 
ORNITHOLOGISTS’ UNION CHECK-LIST OF 
NORTH AMERICAN BIRDS. 
THE Sixteenth Supplement, the only one since the appearance 
of the Third (1910) Edition of the American Ornithologists’ Un- 
ion ‘Check-List of North American Birds,’ was published in July, 
1912. Since that time it has for various reascns not been ex- 
pedient to publish further decisions. The Committee on Nom- 
enclature, since its reorganization at the A. O. U. meeting in 
November, 1919, has decided to begin the preparation of a new 
A. O. U. ‘Check-List.’ This is undertaken as part of the coopera- 
tion between the British Ornithologists’ Union and the American 
Ornithologists’ Union in the production of a series of lists of the 
birds of the several zoogeographical regions of the world, and will 
probably be issued as the Nearctic volume of the proposed ‘Sys- 
tema Avium.’ 
Since the publication of the last A. O. U. ‘Check-List’ the great 
activity among American ornithologists has resulted in an almost 
unbelievable number—several hundreds—of additions and changes 
most of which have been listed from time to time in ‘ The Auk’ and 
will have the consideration of the A. O. U. Committee. As fast 
as these cases are disposed of, it is planned to publish the decisions 
in supplements to the ‘Check-List,’ in order that those who have 
occasion to use the names of North American birds may have the 
benefit of the opinions of the Committee. 
