208 



Div. 1. VERTEBRATE ANBIALS— AVES. 



Class 2. 



Fig. 106.— Slernum of Tonraco. 



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 cerdcal vertebra ; and the sternum, 

 though singulariy 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 tlie 

 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 {Mmophaga, 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, tillin one species it for- 

 cibly recalls to mind that of a Toucan. Another is of great size, approaching the stature of a Curasso w, and has 

 a splendid curled crest, resembling that of several of those birds. 



A third genus consists of 



The Nape-crests {Chizceris, Swainson), — 

 "Which have a rounded beak approaching that of some Trogons, and hard and sombre mottled plimiage, 

 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 Phasianut 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, 

 whicli we conceive miglit be arranged most naturally as follow. 



I. ScANSOREs, as limited to the Parrots. 



II. Raptores, or the Birds of Prey; which subdivide into two thoroughly distinct 

 sections. 



III. Strepitores, Screeckers, consisting of all the remainder that are not organized upon 

 the definite type of the Passeri7ice. It is necessary to subdivide them first into three series, 

 wliieh might be designated Syndactyli, Zygodactyli, and Heterodactyli ; the two first of 

 which names, liowevcr, do not rigidly apjdy in every instance, the groups being founded rather 

 upon the aggregate of the organization, than ujion any single character. 



1. Syndactyli. — These, with the exception of the Motniots, 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 llalcyoides. 



