IVORY GULL. 301 



men is an inch shorter, and has the tarsus only 2 inches 2 lines long j 

 a third individual is of intermediate dimensions. 



SHORT-BILLED MEW GULL. 



(Larus brachyrhynchus, Richard. North. Zool. ii. p. 422.) 

 Sp. Charact. — With a short, thickish bill; the tarsus scarcely 2 

 inches long ; quills not tipped with white : a short white space on 

 the 2 exterior ones, and blackish shafts. 



The specimen described by Dr. Richardson was a fe- 

 male, killed on the 23d of May, 1826, at Great Bear Lake. 

 Some brown markings on the tertiaries, primary coverts and 

 bastard wing, with an imperfect subterminal bar on the tail, 

 point it out as a young bird, in the spring moult. The bill is 

 shorter than in Ij. zonorhynrJius, and stouter than in L. ca- 

 nus, and like it, is wax-yellow, with a bright yellow rictus 

 and point. Its tarsus is nearly one third shorter than that 

 of the Ring-Billed Gull. 



Length 19 inches ; wing 13^ ; of the bill above, I4 inches ; tarsus 

 1 inch 11 lines. 



IVORY GULL. 



(Larus ehurneus, Gmel. Lath. Ind. sp. 10. Temm. ii. p. 7C9. Boxap. 

 Syn. No. 297. Richard. North. Zool. ii. p. 419. Ivory Gull 

 Penn. Arct. Zool. ii. p. 529. No. 457. La Mouette Blanche, 

 Buff. Ois. viii. p. 422. PI. Enlum. 994.) 



Sp> Charact. — Pure white; bill stout; feet black; naked space 

 above the tarsus very small ; webs of the feet somewhat indented ; 

 tarsus Is^ inches ; first primary longest. — Young ; lores and chin 

 dusky-grey, dark brownish spots on the wing coverts and scapu- 

 lars, with bars of the same on the end of the tail and tips of the 

 quills : bill blackish, pale at the tip. 

 26 



