220 
AVES. 
Fig. 106. — Sternum of Touraco. 
which at once indicates the propriety of arranging it in the present series, among which it is most 
nearly related to the Toucans. They have but twelve true cervical vertebrae ; and the sternum, 
though singularly small, presents no affinity for that of the Poultry. The stomach is large and 
but slightly muscular, extending into the abdominal por- 
tion of the cavity of the body ; and the intestines are short 
and without coeca. Unlike the Toucans, however, they possess 
a small gall-bladder; but the tongue, at least in some of 
them, is similarly barbed towards the tip. The feet have the 
first and fourth toes directed laterally, for which reason they 
commonly perch lengthwise on the horizontal branches of 
trees, which they perambulate longitudinally, clasping the 
bough with their two laterally disposed toes, while the others 
are directed forwards. Their movements are light and elegant 
in the extreme, a particular in which they differ remarkably 
from the Colies : they pass with an easy sailing flight from tree 
to tree; live in pairs or families according to the season; 
subsist almost exclusively upon fruits, and lay four delicate 
white eggs in the hollows of decayed timber]. 
Such are 
The Touracos {Corythaix^ Illiger), — 
The beak of which does not ascend upon the forehead, [and 
is generally much compressed] , and the head is adorned with an erectile crest. 
[Seven species are now known, the ground-colour of which is generally vivid-green, with some gorgeous crimson 
on the open wing. We should observe, that in all this group the feathers are very short upon the rump, being the 
reverse of what obtains throughout the Poultry. The head, however, is small, as in the latter.] 
The Plantain-eaters {Musophaga, Isert), — 
Are so named from the fruit on which they subsist, and are characterized by the base of the bill forming 
a disk, which covers part of the forehead. 
[They grade, however, into the former, the beak becoming more and more inflated, till in one species it for- 
cibly recalls to mind that of a Toucan. Another is of great size, approaching the stature of a Curassow, and has 
a splendid curled crest, resembling that of several of those birds. 
A third genus consists of 
The Nape-crests {CMzceris, Swainson), — 
Which have a rounded beak approaching that of some Trogons, and hard and sombre mottled plumage, 
very unlike that of the others. Their exterior toe is more limited in its range outward by the con- 
necting membrane. 
Two species are well known, both from Africa, like all the preceding, — one the Phasianus Africanus of Latham. 
We here, at length, arrive at a sufficiently marked interruption of the series of the class of 
Birds, to be enabled to introduce some remarks on the affinities of the preceding orders, 
whieh we conceive might be arranged most naturally as follow. 
I. ScANSORES, as limited to the Parrots. 
II. Raptores, or the Birds of Prey; wffiich subdivide into two thoroughly distinct 
sections. 
III. Strepitores, Screechers, consisting of all the remainder that are not organized upon 
the definite type of the PasserincB. It is necessary to subdivide them first into three series, 
which might be designated Syndactyli, Zygodactyli, and Heterodactyli j the two first of 
wffiich names, however, do not rigidly apply in every instance, the groups being founded rather 
upon the aggregate of the organization, than upon any single character. 
1. Syndactyli. — These, with the exception of the Motmots, are exclusively animal-feeders, 
like the Raptores, to which they succeed; and even the Motmots subsist more upon animal 
than upon vegetable diet. They fall under two principal ’minor groups, which we term 
Buceroides and Halcyoides. 
