88 
SLATE-COLOURED HAWK, 
of this genus are subject, that unless the naturalist has recourse 
to those parts that are subject to little or no alteration in the full- 
grown bird, viz. the particular conformation of the legs, nos- 
trils, tail, and the relative length of the latter to that of the 
wings, also the peculiar character of the countenance, he will 
frequently be deceived. By comparing these, the same species 
may often be detected under a very different garb. Were all 
these changes accurately known, there is no doubt but the num- 
ber of species of this tribe, at present enumerated, would be 
greatly diminished; the same bird having been described, by 
certain writers, three, four, and even five different times, as so 
many distinct species. Testing, however, the present Hawk 
by the rules above-mentioned, I have no hesitation in consid- 
ering it as a species different from any hitherto described; and 
I have classed it accordingly. 
The Slate-coloured Hawk is eleven inches long; and twenty- 
one inches in extent; bill blue black; cere and sides of the 
mouth dull green; eye-lid yellow; eye deep sunk under the pro- 
jecting eyebrow, and of a fiery orange colour; upper parts of a 
fine slate; primaries brown black, and, as well as the seconda- 
ries, barred with dusky; scapulars spotted with white and 
brown, which is not seen unless the plumage be separated by 
the hand; all the feathers above are shafted with black; tail very 
slightly forked, of an ash colour, faintly tinged with brown, 
crossed with four broad bands of black, and tipt with white; 
tail three inches longer than the wings; over the eye extends a 
streak of dull white; chin white mixed with fine black hairs; 
breast and belly beautifully variegated with ferruginous and 
transverse spots of white; femorals the same; vent pure white, 
legs long, very slender, and of a rich orange yellow; claws 
black, large, and remarkably sharp; lining of the wing thickly 
marked with heart-shaped spots of black. This bird on dissec- 
tion was found to be a male. In the month of February, I shot 
another individual of this species, near Hampton in Virginia, 
which agreed almost exactly with the present. 
