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,[26] the present list comprises only ornithological cases—i. e., such as require specimens or the identification 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 December 31, 1918, and nothing after that date has been taken. In view of the volume and widely scattered character of current ornithological 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[27] and Changes in Names.
Gavia arctica (Linnæus) becomes, so far as North American specimens are concerned, Gavia viridigularis Dwight, ‘The Auk,’ XXXV, No. 2, April, 1918, p. 198 (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, 1918, pp. 198-199.)
†Larus hyperboreus barrovianus Ridgway. Larus barrovianus Ridgway, ‘The Auk,’ III, No. 3, July, 1886, p. 330 (Point Barrow, Alaska). Reinstated as a subspecies. (Cf. Oberholser, ‘The Auk,’ XXXV, No. 4, Oct., 1918, p. 472.) Range: northwestern North America, south in winter to California.
Thalassogeron Ridgway becomes Thalassarche Reichenbach (Natürl. Syst. Vögel, 1852, p. V), because not considered generically separable. (Cf. Loomis, Proc. Calif. Acad. Sci., ser. 4, II, pt. II, No. 12, April 22, 1918, p. 44.)
Thalassogeron chrysostomus culminatus (Gould) becomes Thalassarche culminata culminata (Gould), because Diomedea chrysostoma Forster is considered not with certainty identifiable. (Cf. Loomis, Proc. Calif. Acad. Sci., ser. 4, II, pt. II, No. 12, April 22, 1918, p. 85.)
Fulmarus rodgersi Cassin becomes Fulmarus glacialis rodgersii Cassin, because not specifically distinct from Fulmarus glacialis. (Cf. Loomis, Proc. Calif. Acad. Sci., ser. 4, II, pt. II, No. 12, April 22, 1918, pp. 88-90.)