266 Descriptions of two New Species of Gulls. 



Rissa septentrionalis. 



The North Pacific Kittiwake. 



Adult. Head, neck, under surface, bend of the wing and 

 tail pure white ; back and wings light pearl blue ; the first 

 primary is black for about half its length from the end, with a 

 white spot one and a half inches long, crossing both webs near 

 the tip, which is black ; the second primary is black for about 

 one third the distance from its end, and having also a white 

 spot (but less in extent) inside the black tip, the next five pri- 

 maries are black at their ends, with white tips, but the black 

 decreases in extent from the second, until it exists only as a 

 spot on the seventh ; basal portion of the primaries bluish-ash 

 fading into white where it joins the black, except on the first 

 and second ; secondaries and tertiaries terminating with white; 

 bill of a dusky-green for two thirds its length from the base, 

 apical third yellow, which deepens to orange on the ridge of the 

 upper mandible, and the angle of the lower; tarsi and feet 

 yellowish-green. 



Length 17* inches; wing 1Z\ ; tail 5£; bill U ; tarsi 11. 



Habitat. — Pacific coast of N". Am., Puget Sound. 



This species does not differ much in size from R. tridactylus, 

 but in color it is rather more grey, the tarsi and wings are 

 Longer, with the black on the ends of the latter more extended; 

 the hind-toe is more developed than in H. tridactylus. 



There have been placed in my hands for examination, a large 

 number of specimens of the family Laridre, which form part of 

 the magnificent collection of birds belonging to the Smithsonian 

 Institution at Washington ; among them I found the two species 

 now described as new. 



