INTRODUCTION. 
vi 
only a single species has yet been discovered. It is in South America, however, that we find 
the greatest number of species, and those of the most exquisite plumage : nor is this all; for it 
will be further observed that, in accordance with the great geographical distribution thus 
pointed out, there exist certain characters common to the species inhabiting each region, 
which, although not very apparent to the unpractised eye, constitute the basis of generic 
subdivisions, and doubtless have an influence upon their habits and manners. Between the 
American species, and those inhabiting India and Africa, we not only find this broad line of 
distinction, but discover moreover that the birds of each country are themselves naturally 
resolvable into certain minor groups, each possessing its peculiar characters, and each as 
different in habits as in form. 
The beautiful species of the group to which the sub-generic title of Calurus has been 
applied, distinguished by a redundancy of flowing plumage, are not, as may be expected, so well 
fitted for flight, or for taking their prey on the wing, as are the more closely-plumed species to 
which the generic name of Trogon is now restricted ; accordingly Mr. Natterer informs me that 
the gorgeous birds of the former group tenant the topmost branches of the loftiest forest trees, 
clinging beneath them like Parrots, and feeding more exclusively on fruits and berries; while 
on the other hand, Mr. W. S. Mac Leay states that the singular Trogon inhabiting Cuba, (the 
only example of the sub-genus Temnurus ) which approximates to the Woodpeckers in the more 
lengthened form of the bill, in the rigid character of the outer tail-feathers, and in the spotting 
of the wings, approaches these birds also in its habits, giving a preference to the holes of 
trees rather than to the branches, from the bark of which it procures the larvae and various 
insects which constitute its food. 
The habits of the Old World species are unfortunately much less known than those of 
their American relatives. From the more robust form of their bill and their wide gape, I am 
inclined to suspect that they feed even still more exclusively on insects than on fruits; indepen¬ 
dently, however, of the greater strength of the bill, the non-serration of the edges of the man¬ 
dibles, and the half-denuded face, they may at all times be distinguished by the rich brown 
colouring of the backs of the males, and by the entire absence of bars across the outer tail- 
