316 Observations upon the Affinities 



Among the many distinctions which subsist betwixt the 

 Rapaces and Cantrices, one of the most prominent consists in 

 the diverse modification of the stomach, which in the Hete- 

 rogenes is variously intermediate. The shape of the egg is 

 nearly spherical in the Rapaces, and considerably more elon- 

 gated in the Cantrices; and in this, also, a gradation from 

 one to the other is effected in the series of Heterogenes. 



In the circumstance of retaining the first plumage till the 

 second autumn, again, the rollers, bee-eaters, and kingfishers, 

 which three families have also the least muscular stomachs, 

 and lay the most globular eggs, would seem to have the best 

 claim to be ranged immediately following the Rapaces ; but 

 a better series may be formed by commencing with the horn- 

 bills, in which the muscular coat of the stomach is much 

 thicker. To proceed. — 



Tongue very small, short, and heart-shaped. Intestine short and with- 

 out cceca. Sternal conformation peculiar ; the posterior edge of the breast- 

 bone with only one slight emargination on each side. Feet typically syn- 

 dactyle. Tail consisting often feathers only. Example, Buceridce ; hornbills. 



" Stomach a membranous bag."* Sternum more deeply emarginated. 

 Feet ccenodactyle. Ex. Upupidce ; hoopoes. 



Sternum doubly emarginated. Twelve tail-feathers. Ex. Coracidce ; 

 rollers, (Coracias and Eurystomus). With the feet syndactyle. Ex. Me- 

 ropidce ; bee-eaters : (Merops and Nyctiornis). Haley onida ; halcyons and 

 kingfishers. 



Tongue lengthened, tapering, and very thin. Stomach more muscular. 

 Intestine extremely short, and furnished with large cceca. Ex. Todidee ; 

 todies. With the outer toe reversed. Ex. Galbulida ; jacamars. 



Tongue laterally barbed. Stomach as in preceding.! The cceca proba- 

 bly absent. Only ten tail-feathers in some. Feet syndactyle. Ex. Prio- 

 nitidce ; motmots. 



Feet zygodactyle, having the outer toe reversed. No cceca. Only ten 

 tail-feathers. Ex. Rhamphastida ; toucans and aricaris. 



Tongue barbed only towards the extremity. The feet having the first 

 and fourth toes disposed laterally. Ex. Musophagidce, in part; or the tou- 

 racos, (Corythaix), plantain-eaters, (Musophaya), and napecrests, (Chizcerhis) 

 With all four toes having a forward tendency ; the foot being plantigrade. 

 Tongue not barbed. Ex. Musophayidce, the remainder; or the colies, 

 (Colius). 



Tongue very peculiar: the oesophagus dilated into a crop, which becomes 

 glandular during incubation: intestine very long and slender. Sternal ap- 

 paratus differing very considerably from the rest, having a small foramen, 

 at most, in place of an emargination : the furcula absent in some.J Inferi- 

 or larynx complicated, and operated upon by three pairs of muscles. Feet 

 plantigrade, and zygodactyle. Twelve tail-feathers, &c. &c. Ex. Psitta- 

 cida; parrots. 



*Selby. fLeVaillant. 



J In some Rhamphastida the clavicles are separate and very short. 



