48 



AXXALS OF THE CaRNECIE MuSEUM. 



solid and terminal i)ieces that support on their outer aspects the 

 articular facets for the vertebra; before and behind it. The neural 

 spine is reduced to a sharp line ; the posterior zygapophyses are out- 

 standing processes. The sixth, seventh, eighth, and ninth \ertebrae 

 are substantially the same in character as the fifth, though they are 

 growing shorter as we proceed backwards. They show also the open 

 carotid canal. In the tenth vertel)ra this is replaced again by a hypa- 

 pophysis, a single plate placed anteriorly on the centrum beneath. 

 The vertebral canal is still a closed passage, and the neural spine is 

 absent. Extensive pneumatic foramina exist in all the ultimate seg- 

 ments of the cervical division of the sj^inal column. The eleventh and 



Fi(>. 15. The stenuiin o{ iVui/ioiiits loiii^irostris ; right lateral view, natural size. 



twelfth vertebra; are slowly changing, to bring about what we find 

 strongly developed in the thirteenth. In this latter we observe a well- 

 protiounced double neural spine, occupying a mid-position on the neu- 

 ral arch. The postzygapophyses are elevated, but still project out- 

 wards. Anteriorly, the vertebra is very broad from side to side, owing 

 to the far-spreading tran.sverse processes that here overarch the verte- 

 bral canal, it being closed in beneath by the anchylosed ribs, already 

 alluded to above as being a character of this vertebra. The lateral 

 aspects of the centrum show a deep elliptical pit on each side, with 

 numerous circular pneumatic perforations at their bases. The hypa- 

 l)ophysis is a single plate, occupying the mid-portion of the centrum. 

 In the fourteenth vertebra the ribs, or rather the delicate pleura- 

 pophyses, have been liberated ; the hfemal spine exhibits evidences of 

 becoming tricornute ; the neural spine stands well above the vertebra 



