Mr. R. B. Sharpens Catalogue of Accipitres. 237 



The following particulars are given at pp. 283 and 287 of 

 vol. iii. of the work of the above-named authors on the 

 Land Birds of North America. 



Wiug. Tarsus. Middle toe. 



inches. inches. inches. 



In fifty Nortli-American specimens 

 of ^. borealis: 



Males 13-5 -16-5 2-4*-3-2 1-0-1-7 



Females 15-25-17-75 3-15-3-4 1-7--1-8 



In forty-six North-American spe- 

 cimens of B. cahinis : 



Thirty males 13-5 -IG 2-9 -3-3 1-7-1-8 



Sixteen females 10 -17'25 3-3 -3-4 l-8-l-y5 



The authors of the work from which I have extracted the 

 above dimensions, in endeavouring to define the typical or 

 eastern B. borealis, describe it, in vol. iii. p. 257, as having 

 the " tibiae and lower tail-coverts without transverse bars at 

 any age ;" and again, at p. 283, as having the " tibiae and 

 lower tail-coverts immaculate. •* In the same page they 

 remark that 'Hhe true Buteo borealis, as restricted, may 

 always be distinguished from the var. calurus, its western 

 representative, by its having the posterior lower parts (tibiae 

 and lower tail-coverts) entirely free from transverse bars, and 

 by lacking indications of transverse bars on the tail anterior 

 to the conspicuous subterminal onef." 



On the other hand, it is stated at p. 284 of the same 

 volume, under the head of " var. borealis, Eastern Red-tail,^^ 

 that an immature specimen . . . from Philadelphia has the 

 tibiae quite distinctly barred, but less conspicuously than in 

 young of var. calurus^ 



My own observations prove that some specimens from the 

 eastern regions of North America, the acknowledged home of 

 the typical B. borealis, do not possess the immaculate tibiae 

 which are considered by the authors above quoted to be a 

 distinctive attribute of that race ; and I therefore believe 



* This stands in the original 14, which I take to be an obvious mis- 

 print. 



t The last character is probably intended to apply only to the adult 

 bird. 



