NATATORES. 



379 



than has yet been determined. It is arranged by the Prince Bona- 

 parte, in his genus Leucopliaeus, Conspectus Avium, II, p. 231. 



4. Larus albipennis, Peale. 



Larus albipenm's, Peale, Zool. U. S. Exp. Exp. Birds, p. 288 (1848), 



" Larus alhlpcnnis, LiCHT." Gray, Gen. Ill, p. 654 ? 



Larus cirrocephalus, ViEiLL. Nouv. Diot. XXI, p. 502 (1818) ? 



Capite, collo et corpore siibtm alhis, corpore supra cinereo, pemiis pri- 

 mariis quinque priorihus alhis, intus nigro marginatis, cauda alba. 

 Long. tot. 14 poUices. 



Form. — Rather slender and graceful. Bill moderate or rather long ; 

 wing long, extending, when closed, beyond the end of the tail, 

 which is rather short. Tarsi moderate, rather slender. 



Dimensions. — Total length (of skin), fourteen inches; wing, eleven 

 inches ; tail, four and three-fourths inches. 



Colors. — Head, neck, and entire under parts, white. Back, wing- 

 coverts, tertiaries, secondaries, and shorter primaries, light cinereous. 

 First five primaries white, bordered with black on their inner edges, 

 nearly throughout their length ; first primary edged with black at its 

 base, on its outer web. Tail white. " Bill and feet scarlet ; irides 

 brown." 



Hab. — Coast of Chili. Specimen in Nat. Mus. Washington. 



This is apparently the young bird of a species distinct from any 

 other known to us, though probably the same as referred to by Lich- 

 tenstein, under the same name, as above given. We have, however, 

 not succeeded in finding a description under this name in any of the 

 works of Lichtenstein to which we have access. It is cited as " L. 

 albipennis, Licht. MSS.," by Mr. Gray, in " List of the Specimens of 

 Birds in the Collection of the British Museum," Part HI (London, 

 1844), and is not to be found at all in Prof. Liclitenstein's " Nomen- 



