Mr. R. B. Shay'pe’s Catalogue of Accipitres. 237 
The following particulars are given at pp. 283 and 28 7 of 
vol. iii. of the work of the above-named authors on the 
Land Birds of North America. 
In fifty North-American specimens 
of B. borealis: 
Wing. 
inches. 
Tarsus. 
inches. 
Middle toe. 
inches. 
Males . 
13-5 -16*5 
2-4*~3-2 
1-6-1-7 
Females. 
In forty-six North-American spe¬ 
cimens of B."calurus: 
15-25-17-75 
3-15-3-4 
1-7-1-8 
Thirty males. 
13-5 -16 
2-9 -3-3 
T7-T8 
Sixteen females. 
16 -17-25 
3-3 -3-4 
1-8-1-95 
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. 25 7, as having 
the “ tibiae and lower tail-coverts without transverse bars at 
any age ; 33 and again, at p. 283, as having the “ tibiae and 
lower tail-coverts immaculate . 3 In the same page they 
remark that f<r the 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 
tibise 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 tibise 
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. 
