_Cathartes_, AUCT. (in part). (Type, _Vultur aura_, L.)
GEN. CHAR. Size medium (about equal to _Neophron_), the wings and tail
well developed, the remiges very long and large. Head and upper portion
of the neck naked; the skin smooth, or merely wrinkled; a semicircular
patch of antrorse bristles before the eye. Nostril very large, with
both ends broadly rounded, occupying the whole of the nasal orifice.
Cere contracted anteriorly, and as deep as broad; lower mandible not so
deep as the upper. Plumage beginning gradually on the neck, with broad,
rounded, normal feathers. Ends of primaries reaching beyond the end of
the tail; third or fourth quill longest; outer five with inner webs
appreciably sinuated. Tail much rounded; middle toe slightly longer than
the tarsus. Sexes alike.
[Illustration: _R. aura._ ¼ nat. size.]
[Illustration: _R. aura._ (¼.)]
[Illustration: _R. burrovianus._ (¼.)]
[Illustration: _Neophron percnopterus._ (¼.)]
[Illustration: _Rhinogryphus aura._ (¼.)]
The species of this genus are only two in number, one of them (_aura_)
extending over the whole of America, with the exception of the colder
portions; the other (_burrovianus_) confined to the eastern tropical
region. They may be distinguished as follows:—
Species.
COMMON CHARACTERS. General plumage nearly uniform blackish; no white.
_Adult._ Bill white; head reddish. _Young._ Bill and head dusky, or
blackish.
1. =R. aura.= Upper half of the neck bare all round. Feathers of the
upper surface with brown borders. Wing, 20.00–23.00; tail, about
12.00. _Hab._ Entire continent and islands of America, except the
colder portions.
2. =R. burrovianus.=[98] Only the head and throat naked, the
feathers of the neck extending up to the occiput. Feathers of the
upper surface without brown borders. Wing, 18.00–18.50; tail, 9.00.
_Hab._ Eastern Tropical America (Brazil; Eastern Mexico??).
Rhinogryphus aura (LINN.).