R. aura. ¼ nat. size.
R. aura. (¼.)
R. burrovianus. (¼.)
Neophron percnopterus. (¼.)
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:—