266 Proposed Changes in the A. 0. U. Check-List. [April 



FOURTH ANNUAL LIST OF PROPOSED CHANGES IN 



THE A. O. U. CHECK LIST OF NORTH AMERICAN 



BIRDS. 



BY HARRY C. OBERHOLSER. 



This is the Fourth Annual List of proposed A. O. U. Check-List 

 additions and changes in the names of North American birds. 

 Like the First, Second, and Third, 1 the present list comprises only 

 ornithological cases — i. c, such as require specimens or the iden- 

 tification of descriptions for their determination — and consists of 

 additions, eliminations, rejections, and changes of names due to 

 various causes. However, only changes known to be the result 

 of revisionary work are included; therefore no mention is here 

 made of changes involved in names in local lists or elsewhere, 

 used without sufficient explanation or not known to be based on 

 original research, of changes or additions queried or but tentatively 

 made, or of the elimination of subspecies by authors who, on general 

 principles, recognize no subspecies. 



This list is intended to include everything pertinent up to Decem- 

 ber 31, 1918, and nothing after that date has been taken. In view 

 of the volume and widely scattered character of current ornithologi- 

 cal literature, it is not at all unlikely that some names or changes 

 have been overlooked, and the writer would be very thankful for 

 reference to any omissions, in order that such may be duly given 

 a place in next year's list. 



Additions - and Changes in Names. 



Gavia arctica (Linnaeus) becomes, so far us North American specimens 

 are concerned, Gavia viridigularis Dwight, ' The Auk,' XXXV, 

 No. 2, April, 1918, p. 19S (Gichega, northeastern Siberia). (Cf. 

 Dwight, ' The Auk,' XXXV, No. 2, April, 1918, pp. 196-199.) 



Gavia pacifica (Lawrence) becomes Gavia arctica pacifica (Lawrence). 

 (Cf. Dwight, ' The Auk,' XXXV, No. 2, April, 191S, pp. 198-199.) 



'For the three previous lists see, 'The Auk,' XXXIII, October, 1916, pp. 425-431! 

 XXXIV, April, 1917, pp. 198-205; XXXV, April, 1918, pp. 200-217. 



1 Additions to the A. O. U. Check-List, the Sixteenth Supplement, and the First, Second, 

 and Third Annual Lists, are marked with a dagger (f). 



