Mr. R. B. Sharpe’s Catalogue of Accipitres. 237 
The following particulars are given at pp. 283 and 287 of 
vol. ii. of the work of the above-named authors on the 
Land Birds of North America. 
Wing. Tarsus. Middle toe. 
inches. inches. inches. 
In fifty North-American specimens 
of B. borealis : 
AEN) oat ae ES ean ear 13°56 -165 =. 2°4*-8'2—-16-1°7 
Females ..... ein cee 15°25-17'75  3:15-3:4—1:7--1'8 
In forty-six North-American spe- 
_cimens of B. calurus : 
Pap TU OOS ii oh casts sell k= 13:5 -16 2:9 -3°3  1:7-18 
Sixteen females ,....... wee. 16 -17:25 33 -3:4 = 18-195 
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. 11. p. 257, as having 
the “ tibiz and lower tail-coverts without transverse bars at 
any age ;” and again, at p. 283, as having the “tibie and 
lower tail-coverts immaculate.’ In the same page they 
remark that. “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 onet.”’ 
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 
tibize 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 tibize 
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 1:4, which I take to be an obvious mis-~ 
print. 
+ The last character is probably intended to apply only to the adult 
bird. 











