BIEDS LARIDAE — LAEUS OCCIDENTALIS. 



845 



List of specimens. 



LAKUS OCCIDENTALIS, Audubon. 



The AVestern Gull. 



Larus occidentalis, Add. Orn. Biog. V, 1839, 320— Aud. Birds Am. VII, 1844, 161. 

 Laroides occidentalis, Brcch, Cab. Jour. 1855, 282. — Bon. Cons. Av. II, 1856, 219. 



Sp. Ch. — Adult. The head, neck, rump, tail, and under plumage, pure white ; the back and wings grayish blue, many shades 

 darker than in L. argenlatus; the first si.^ primaries are black towards their ends, extending on the first for about half its length, 

 and lessening on the others, until on the sl.xth it is reduced to a narrow sub-terminal bar ; the tips of all are white, on the first 

 the while is an inch and a half in e-xtent, and crossed near the end with black ; secondaries and tertiaries with broad white tips; 

 'ris gray ; bill deep yellow, with a bright orange red spot on the angle of the lower mandible ; legs and feet flesh color. 



Young mottled with lead colored brown, grayish white, and brownish ash, lighter on the lower parts ; primaries blackish 

 brown; bill brownish black, dull yellow at base; legs and feet brownish flesh color. 



Length, 25 inches; wing, 17; tail, 7; bill, Sj ; depth at angle, I; tarsus, 2 J. 



Hob. — Northwest coast of North America. 



There are numerous specimens of all ages of this well marked species in the collection ; it is 

 easily distinguished from L. argentalus by its darker colored mantle. A striking characteristic 

 in the young of this species is its very stout bill, which, though much shorter than in the adult, 

 has comparatively great depth at the angle. 



Mr. Audubon's original specimens of this species are now in the private cabinet of Professor 

 S. F. Baird. 



List of specimens. 



