SCANSORES. 
221 
I The Buceroides are distinguished by a very short and heart-shaped tongue, a singly-emar- 
ginated sternum, and ten tail-feathers only ; intestines short, and we believe always without 
cceca ; plumage never vividly coloured. In order to mark the degree of value of the two 
very distinct genera included, we conceive it necessary to indicate the ITornbills by the term 
Appendirostres, and the Hoopoes by that of Arculirostres. Both are peculiar to the eastern 
hemisphere. 
The Halcyoides have a doubly-emarginated sternum, twelve tail-feathers, and, with the 
sole exception of one group of Kingfishers, splendidly coloured plumage. They fall into three 
ij tribes, viz., Cylindirostres, comprising the Rollers, Bee-eaters, and Kingfishers, which have 
; tongues similar to the foregoing, membranaceous stomachs, and no coeca ; a thick skin, firm 
plumage (not moulted the first year), and great power of wing ; nidificating in holes, and pro- 
I ducing numerous shining white eggs, &c. — Angulirostres, composed of the Jacamars and 
1 1 Todies, which have thin, lengthened, lamina-like tongues, muscular gizzards, and great coeca, 
ij resembling those of the Owls; thin skin, soft plumage, feeble powers of flight, and which 
produce coloured or speckled eggs, also in holes ; — and Serratirostres, or the Motmots, which 
III are intermediate to the Cylindirostres and the Toucans, (which commence the next series). 
The Angulirostres and Serratirostres are confined in their distribution to America ; while the 
'!' Cylindirostres, with the exception of a single subdivision of Kingfishers partly, are found only 
in the old world. 
I 2. Zygodactyli. — The members of this division likewise fall into two principal minor 
groups, which may be termed Picoides and Cuculoides. The greater number subsist on mixed 
j diet, and a marked predatory propensity is retained by some. 
The Picoides have always (at least in every knowm instance) a doubly-emarginated sternum, 
comparatively muscular gizzard, and no cmca to the intestine. They all produce white eggs, 
less spherical than those of the Syndactyli, (in which respect the latter approximate the 
j Raptores, w^hich precede them) ; and have an accessory plume to their feathers, more or less 
developed; their plumage being almost always adorned with vivid colours. It is in this 
j group that the tongue is so variously modified, in the Toucans, Woodpeckers, &c. To bring 
j the species as near as possible together, they may be arranged into two tribes, viz., Leviros- 
i tres, consisting of two very distinct families, — that of the Toucans, and that of the Touracos 
I and Colies ; and Cuneirostres, comprehending the Woodpecker family (which includes the 
j Honeyguides), and that of the Barbets. The Toucan and Touraco families are respectively 
peculiar to the old and new worlds, the latter, with the sole exception of two or three Colies, 
|l to Africa; the Woodpeckers are generally diffused, excepting in Australia; and members of 
I the Barbet family are found in the warm regions of both hemispheres. 
The Cuculoides have a comparatively lax stomach, and invariably great coeca, which when- 
i ever they occur throughout the Strepitores are always of the same proportional dimensions 
i and form as those of the nocturnal Birds of Prey : their colours, excepting in one group of 
; Cuckoos, are never bright ; and they have no trace of an accessory plume to the feathers : 
' the greater number lay coloured or speckled eggs, and many construct inartificial nests in 
i; bushes, (all the preceding genera, save the Colies only, resorting to holes for that purpose). 
I A great proportion of them have the outer and middle toes more or less directed laterally. 
|| They fall under two families only, that of the Courols, Barbacous, and Puff- birds, which have 
I; twelve tail-feathers, and that of the Cuckoos, which have only ten or fewer, and which might 
' be again naturally distributed into several supergeneric divisions, or subfamilies. Of these, 
w^e can only remark, that that which comprises the parasitic species is peculiar to the 
old world. 
3. Heterodactyli. — This group consists of Birds the great majority of which are mainly 
insectivorous, and take their food on the wing. They are generally endowed, therefore, with 
considerable power of flight, have a wide gape, and short feet, rarely adapted for progression. 
The only zygodaetyle family of them has the toes differently disposed from those of all other 
