244 On the Adult Dress of the Labrador Falcon. 



dark colour of the upper parts in the Labrador Jerfalcon is 

 much more sooty ; the light transverse markings are not 

 only much darker than in the Norwegian Jerfalcon, but also 

 less developed ; they are narrower and do not nearly reach 

 the shafts ; the rump is uniform, without any trace of 

 transverse markings ; the thighs are dark slaty, with buffy- 

 white transverse spots, and not buffy white with dark trans- 

 verse bars, as in the adult Norwegian Jerfalcon ; while the 

 inner webs of the primaries are not barred, but slightly 

 marbled with buff. 



By these characters we can infallibly recognise the beautiful 

 specimen in the British Museum (No. 90.3.13.1) from 

 Canada as Hierofalco labradorus. It is an old bird with 

 yellow legs, perceptible even in the skin*. The general 

 colour above is very dark brown, conspicuously washed with 

 bluish ; the top of the head is very dark, somewhat darker 

 than the mantle, with no markings at all. The ear-coverts 

 are uniformly dark, like the top of the head. The mustachios 

 are not detached from the ear-coverts. The upper back is 

 uniform in colour, with scarcely perceptible light spots on 

 the margins of some of the feathers. The upper surface of 

 the wing is like the upper back. The lower back and rump 

 are decidedly more bluish than the upper back, of a dirty 

 smoky blue. The under parts are very much spotted, dark 

 brown in general colour, with pale buff transverse spots. 

 The under tail-coverts are barred, but the dark bars are 

 very much broader than the light bars — quite the reverse of 

 the state of things in Hierofalco gyrfalco. The wing-linings 

 are as dark as the under parts of the body ; the under surface 

 of the primaries is of the same character as in the young 

 bird, the light bars being replaced by nearly inconspicuous 

 markings. 



Thus the adult Labrador Jerfalcon differs very much in its 

 coloration from the young, and the slight modifications, 



* After looking over a number of specimens of Jerfalcons and Sakers, 

 both in the flesh and in skins, we have come to the conclusion that the 

 yellow colour of the legs is perceptible in dried as well as in fresh 

 specimens. 



