OF GALLINACEOUS BIRDS AND TINAMOUS. 169 



ossified in the Curassow, and is coalesced with its "prevomers," the splints of this same 

 region. 



This is extremely inte resting to the embryologist, and is a great step upwards 

 towards the most instructive condition of these parts in the Syndactyle, Zygodactyle, 

 and Raptorial groups on the one hand, and the " Cultrirostes," " Lamellirostres," and 

 " Totipalmatce " on the other. As in Corythaix, there is either no vomer or but a rudi- 

 ment, as in Fowls. I have not been able to find one in this tribe ; yet it may have 

 been lost, each time, in preparing the skull. The mass of bone forming the ossified 

 preseptal cartilage and the prevomerine splints is very thick and spongy, only a 

 degree below what is seen in Corythaix. In the Pigeons the prevomers are cellular, but 

 the septum does not ossify. The nasals are typical in Crax : they are high and splint- 

 like ; but their broad frontal ends are spongy, and rise a little where they coalesce with 

 the frontals ; in front of this thick portion they are extremely elastic, and admit of free 

 bending at the hinge. A good part of the nasal processes of the premaxillaries con- 

 tinues distinct; just where they coalesce they rise into scabrous masses, which lie 

 within the " cere." The rest of the premaxilla is typical ; it is high, arcuate, and 

 trenchant at the edges, and the angles are, as in Tetrao urogalliis, very free of, and con- 

 siderably below, the fiat, feeble zygomatic processes of the "prevomers." The jugals 

 and quadrato-jugals are, as usual, splint-like and rather weak. As in the Talegalla, 

 the palatines show a somewhat higher degree of development than in the types ; for 

 there is a trace of the external palatine groove — that which forms such a strong channel 

 in many birds. 



There is but little to be remarked about the thick pterygoid, save that the facets for 

 articulation with the basi-sphenoid are very long, as in Tetrao urogallus. This bone 

 embraces the skull-balk more perfectly than in either the type or the subtype, and thus 

 comes nearer the higher birds. Compared with those of the Turkey, the mandibles 

 of the Curassow are more arched (in the side view), are deeper, and have the splint- 

 pieces equally well developed, thus filling in all the membrane which is so open in the 

 " Tetraonidse:" the condyles and angular processes are quite typical. The structure 

 of the OS hyoides is quite the counterpart of that of the Fowl. 



There are sixteen cervical vertebrae in Cj-ax globicera, all perfectly typical ; the last 

 two bear free ribs. There are four dorsal vertebrae, the last free, and the others forming 

 one piece with the last cervical. There are about sixteen sacral vertebrae, the first or 

 which bears ribs that articulate with the expanded top of the last haeniapophysis. The 

 six caudal vertebrae are very strong ; the last, or compound bone, is nearly an inch and 

 a half in length, and has large, forked, coalesced hypophyses. The penult and ante- 

 penult have hypophyses ; but they only articulate with the centrums. 



In Crax globicera I found nothing essentially different in the structure of the diges- 

 tive and vocal organs from those of the typical Fowl, Peafowl, and Turkey. 



z2 



