APPENDIX N. 1 fi] 



APPENDIX N. 



On the Existence in North America of Hierofalco gyrfalco, 

 and its possible Hybridism with H. holboelli. 



In the ' Iljis ' for 1882, pp. 582, 583, I quoted some memo- 

 randa, which I made in 1870 and 1872, respecting some 

 North-American Gyrfalcons which had been sent to this 

 country for examination from the Smithsonian Institution, 

 and which I was then disposed to consider as not separable 

 from Hierofalco islandus. 



Subsequently to the completion of my notes on the 

 Gyrfalcons, four of the specimens above referred to, with 

 some others, were, through the good offices of Mr, Hidgway, 

 sent to me for further examination. A careful comparison 

 of these skins with authentic Scandinavian examples of 

 H. gijrfalco considerably modified the views which I had 

 previously entertained, as will be seen by the following 

 memoranda which I made as the result of the comparisons to 

 which I have alluded : — 



No. 43,144^. Female, ivith four eggs: Fort Anderson 

 (referred to in the 'Ibis' for 1882, pp. 582-584).— This 

 skin corresponds with H. gyrfalco, but not with those speci- 

 mens in which the adult plumage is most fully developed; 

 it agrees with a female of that species, apparently in the 

 plumage of the second year (No. 6 in the Norwich Museum), 

 which was collected by, or for, the late Mr. Wolley at Lang- 

 fjord, in East Finraark, in April or May 1857. The Fin- 

 mark bird has, however, whitish edges to the feathers on the 

 crown of the head, which are wanting in the Fort-Anderson 



