556 ICELAND OR JER FALCON. 



and also at the notchings. Cere, orbits, and legs, yellow, which seems to 

 increase in depth. When I first had it, they were not then tinged with 

 yellow, but the colour of a very white-legged fowl : claws black and 

 powerful, inner one largest. The eye, which is exceedingly bright and 

 piercing, and does not appear to have changed, seems black, but on close 

 inspection, in a good light, is evidently dark-brown. Between the cere 

 and the orbits, and under the eye, the hairy feathers, which lie close, and 

 are pure white, are intermixed with hairs of black, which lie pretty close 

 to the head. 



" Were I to guess the weight, I should say it was double that of the 

 Rough-legged Falcon. The wings reach nearly to the tip of the tail." 



The above detailed account appears to me to furnish a better descrip- 

 tion of the adult Jer Falcon than any that I have met with, and cannot 

 fail to be acceptable to ornithologists. 



On inquiring of a Mr Jones, who had been a resident in Labrador for 

 twenty years, I was informed that these Hawks feed on and destroy an im- 

 mense number of hares, Rock Partridges, and Willow Grous ; but he 

 could not give me any information as to the change of plumage, never 

 having seen them in any other state than that of the individuals repre- 

 sented in my plate, which I shewed to him. The fishermen called them 

 Duck Hawks, and some of them reported many exploits performed by them, 

 which I tbink it unnecessary to repeat, as I considered them exaggerated. 



Falco Islandicus, Lath. Ind. Ornith. p. 32. Adult. — F. rusticolus, Idem, p. 28. 



Adult — F. Gyrfalco, Idem, p. 32. Young — F. sacer, F. oescurus, and F. 



LAGOPUs /S, Idem Temminck, Manual, part i. p. 17 Swains, and Richards. 



Fauna Bor. Amer. vol ii. p. 27. 

 Gyrfalcon, Falco islandicus, Kuttall, Manual, part i. p. 51. 



Male in immature state. Plate CXCVI. Fig. 1. 



Bill shortish, as broad as deep at the base, the sides convex, the dorsal 

 outline curved from the base ; upper mandible cerate, the edges a little 

 inflected, rather obtuse, nearly straight to the tooth-like process, which 

 is rather rounded, the tip trigonal, descending, acute ; lower mandible in- 

 volute at the edges, truncate at the end, with a notch near it on either 

 side, corresponding to the process above. In an individual which I have 

 seen, the margin line of the upper mandible was undulated, or formed a 

 festoon behind the tooth, but in my two specimens, the skin of one of 

 which is now before me, it is quite straight when viewed directly, although 



