Vol. XIX. "j Shufeldt, Maleriiil for a Study of Ike Megapodiidcs. 117 



is practically absent in the lifth ; after that it is ])irKl in order to 

 form tlie open canal for the passage of the carotid arteries. This 

 arterial canal disappears on the thirteenth cervical, where a small, 

 median h;enial sjiine is present on the extreme anterior edge of tlu' 

 centrum, it is more bulky, rudimentary, and further back on the 

 body of the bone in the next two verteljrfe, while in the sixteenth 

 it is much produced to fuse with a similar spine on the leading 

 dorsal (Plate XI., figs. 22, 23). 



On either side, the vertebral canal jxisses tlirough the usual 

 foramina, which here occur in tlie third to the fourteenth cervicals 

 inclusive : on the axis the foramina arc but mere lateral notches. 



The pri'- and post-zygapophyses in the third and fourth 

 vertebra; are united by osseous laminae, either bone being short 

 and rather broad. A small, circular foramina pierces the afore- 

 said laminae on either side in either of these vertebrse. 



In the fifth to the ninth cervicals, inclusive, the pre-zygapophyses 

 are short and bulky, while the hinder pair, in each case, is elongate 

 and directed outwards and backwards. After passing the ninth 

 vertebra they become nearly of a length, while the post- 

 zygapophyses of the sixteenth cervical fuse with the compound 

 bone of the dorsal section of the spine. 



The usual parial spine-like pleurapophyses are developed on 

 the fourth, where they are quite rudimentary, to include the 

 eleventh cervical. On the twelfth and thirteenth they again 

 become rudimentary. 



In the cervical section of the spine the neural canal is cylind- 

 rical in form, to include the twelfth vertebra ; after that its trans- 

 verse axis is appreciably longer than its vertical one. 



Together with the neural spine of the co-ossified sixteenth 

 cervical vertebra, the neural spines of the first, second, and third 

 dorsals form a solid plate of bone, about three centimeters long, 

 and with an average height of some six or seven millimeters. The 

 superior line of this plate-like process of the compound bone of 

 the dorsal section of the vertebral column is nearly straight. The 

 transverse processes of the sixteenth cervical are short and 

 stumpy, while in the case of these fused dorsals they become longer 

 and longer as we proceed backwards, their extremities on either 

 side being solidly united together by metapophysial bars of bone. 

 The centra are transversely much compressed,' with a plate-like 

 haemal spine formed only on the first dorsal, and, as has already 

 been pointed out above, this fuses with a similar development 

 on the centrum of the sixteenth vertebra. Below the body of 

 the first dorsal it is transversely pierced by a foramen (Plate XIII., 

 fig. 28). Longitudinally, in the middle line, these fused dorsals 

 are compressed transversely, and present a sharp edge. This 

 feature entirely disappears in the free fourth dorsal vertebra, 

 which articulates with the compound dorsal segment of the spine 

 and the pelvis. In it, too, the neural spine is lofty, antero- 

 posteriorly narrow, terminating above in a somewliat thickent'd 

 border. Its large diapophyses are the longest of iin\- in the 



