That ail}' subsequent additions to the list be interpolated in 

 sj'stematic order, and bear the number of the species immediately 

 preceding, with the addition of a figure (i, 2, etc., as the case may 

 require), separated from the original number by a period or decimal 

 point, thus giving the intetpolated number a decimal form {e. g., 

 243.1, etc.), in order that the original numbers may be permanent. 



For the convenience of those who may not have the original 

 edition of the A. O. U. Check-I^ist, it may be stated that the 

 concordance gives the equivalent numbers of previous check- 

 lists, in chronological order: B^Baird, 1858; C=Coues, 1873; 

 R=Ridgway, 1880; C=Coues, 1882. 



In the present edition the list of Fossil Birds has been 

 omitted, and a list of Naturalized Species has been added. 



J. A. Allen, 

 William Brewster, 

 Elliott Coues, 

 C. Hart Merriam, 

 Robert Ridgway, 



Committee on Ptiblication. 



