2i THE GYR FALCON— DAWSON'S FALCON. 



bears some resemblance to Prof. Cassin's Heirofalco sacer, especially 

 his description of the young bird, but differs from it in having the 

 claws black ; and the under part of the claws are not greenish- 

 yellow, but of the same hue as the tarsus ; and the general tint of 

 the dark parts of the plumage is not brown, but emphatically slate 

 color. It also somewhat resembles the description given by the 

 same gentleman of the F. atricapillHS or pbimbarms, but differs in 

 having greenish-blue tarsi, and a bluish cere, with black irides." 

 From the date of the capture of this last specimen (iS6i) up to 

 the present year (1876), no other individuals of this rare bird have 

 been met with, and the two birds have remained ticketed in our 

 museum as the Falco Daiosoni (new species Hall !) Recently, 

 however, through the kindness of the Council of the Nat. Hist 

 Soc, both of these birds were placed at my disposal for re-examin- 

 ation and comparison for the present work, and I was enabled 

 notwithstanding the indefinite colors of their plumage to obtain 

 two beautiful and truthful photographs of them. Being strongly 

 impressed with the general likeness of these to the bird figured 

 and described by Audubon as the Falco labradora, but unable to 

 satisfy myself as to their identit)', I forwarded the photographs to 

 Baird and Ridgeway of the Smithsonian Institution at Washing- 

 ton, referring these authorities to Hall's description of the bird in 

 the Canadian Naturalist and Geologist. Shortly afterwards, under 

 date of March iith, 1876, Baird wrote as follows : " I have sub- 

 mitted your notes to Mr. Robert Ridgeway for his criticism, and 

 I give you his replies herewith. Dawson's Hawk is the younger 

 plumage of the same bird as that described by Audubon as Falco 

 labradora, and is one of the local varieties of the Gyrfalcon. I may 

 perhaps write you more fully on the subject hereafter." In a post- 

 cript to this same letter, he adds, probably after a further examina- 

 tion of the plates, '' There is no doubt that F. Dawsoni is the 

 dark stage of Falco Gyr-falco given as F. labradora by Audubon." 



This bird, in one or other of its varieties or stages, it is only 

 natural to suppose, may again be taken in some portion of our 

 Dominion. I therefore, to assist in its identification, append Dr. 

 Hall's original description of it. The portions within brackets are 



