10 
FALCO COOPERII. 
willing to intrust the ultimate revision and superinten- 
dence of this work. 
Our bird agrees very well with the falcon gentle, 
Falco gentihs, Linne; but as that species is referred to 
the young of the goshawk, we have preferred giving it 
a new name to reviving one that might have created an 
erroneous supposition of identity. To the young 
goshawk, our hawk is, in fact, extremely similar in 
colour and markings, being chiefly distinguished from 
it by the characters of their respective sections, having 
the tarsi much more slender and elongated, and the 
wings still shorter ; the tail is also considerably more 
rounded. 
But it is to the sharp-shinned hawk (Falco velox ) 
of Wilson, the Falco Pennsylvanicus, or Falco fuscus in 
its immature plumage, that our Cooper’s hawk bears 
the most striking resemblance, and is in every particular 
most closely allied. Even comparing feather by feather, 
and spot by spot, they almost perfectly agree ; but the 
much larger size of the present, it being more than 
twice the bulk, will always prevent their being con- 
founded, even by the most superficial observer. Another 
good mark of discrimination may be found in the 
comparative length of the primaries; the second in 
F. Cooperii being subequal to the sixth, while in F. 
velox it is much shorter. The latter has also the fifth 
as long as the fourth ; that, in our species, being equal 
to the third. The tail is also much more rounded, the 
outer feather being nearly an inch shorter than the 
middle one. In F. velox the tail is even, the outer 
feather being as long-, or, if any thing, longer than the 
middle. There is no other North American species 
for which it can be mistaken. 
The bird here described, of which we have seen 
seven or eight specimens, perfectly similar in size and 
plumage, was a male, killed in the latter part of Sep- 
tember, near Bordentowu, New Jersey. The stomach 
contained the remains of a sparrow. Another that we 
procured, was shot on the 12th of December, while in 
the act of devouring on the ground a full-grown ruffed 
