158 FALCO ISLANDICUS. 



process is often well formed, and, on the other hand, 

 the festoon is often wanting or indistinct ; and the bird 

 in question is so nearly allied to the Peregrine Falcon 

 in form and proportions, that there seems to me no 

 reason whatever for separating it from the falcons. 

 The same author, by one of his frequent mistakes, cites 

 the F. atricapillus of Wilson, which is nothing but the 

 common goshawk, or a bird most closely allied to it, as 

 a species of the same genus. 



The variations exhibited by the bill, with respect to 

 the festoon and tooth-like process on the edges of its 

 upper mandible, are very remarkable, although not al- 

 together anomalous. It is not, however, quite certain 

 that this species may not, when more accurately ex- 

 amined, be found to be formed of two. Should it 

 prove otherwise, the absence or presence of the tooth 

 in the same species must tend to shew that its uses are 

 not yet properly understood. In all young birds of 

 this genus, that I have examined, it is at first obsolete 

 or small, and gradually enlarges. 



Faleo rusticolus. Linn. Syst. Nat. vol. i. p. 125. Nearly .adult. 

 Faico Gyrfalco. Linn. Syst. Nat. vol. i. p. 130. Young. 

 Falco islandicus candicans. Lath. Iml. Orniih. vol. i. p. 32. Old. 

 Falco rusticolus. Lath. Ind. Ornith. vol. i. p. 28. Nearly adult. 

 Falco Gyrfalco. Lath. Ind. Ornith. vol. i. p. 32. Young. 

 Faucon Gerfault. Falco islandicus. Temm. Man. d''0r7uth. 



p. 17. 

 Jer-Falcon. Falco islandicus. Selby., Illust. voJ. i. p. 36. 

 Gyrfalco candicans. Flem. Brit. Anim. p. 51. 



