CONDOR. 407 
make it at once evident that it was for want of proper exami- 
nation that the Percnopterus, merely on account of its slender 
bill, was ever considered a Cathartes. The remaining cha- 
racters being more of a relative than a positive kind, we shall 
not here notice them, except remarking that the hind toe 
being much shorter and set on higher up in the American 
genus, shows a greater affinity with the gallinaceous birds, 
an affinity which may be traced in other features of their 
organisation. The number of tail-feathers is fourteen in 
several species of vultures, whilst no Cathartes has ever been 
found to have more than twelve. The principal traits, both 
moral and physical, are the same in all the birds composing 
this highly natural family. 
All, in fact, are distinguished by having their head, which is 
small, and their neck, more or less naked, these parts being 
deprived of feathers, and merely furnished with a light down, 
or a few scattered hairs. Their eyes are prominent, being set 
even with the head, and not deep sunk in the socket, as in 
eagles and other rapacious birds. They have the power of 
drawing down their head into a sort of collar formed by 
longer feathers at the base of the neck: sometimes they 
withdraw the whole neck and part of the head into this 
collar, so that the bird looks as if it had drawn its whole neck 
down into the body. They have acrop covered with setaceous 
feathers, or sometimes woolly or entirely naked, and prominent, 
especially after indulging their voracious appetite. Their feet 
are never feathered, like those of an eagle, although they have 
been unnaturally so represented in the plates of some authors. 
The tarsus is shorter than the middle toe, which connected at 
its base by a membrane with the outer one. The claws are 
hardly retractile, comparatively short, and from these birds’ 
habit of keeping much on the ground, instead of always 
perching, as the falconide, they are neither sharp-pointed 
nor much curved. Their wings are long and subacuminate, 
the third and fourth primaries being longest: they are lined 
beneath with a thick down of a peculiar and very soft nature. 
