PROFESSOR OWEN ON THE GENUS DINOENIS. 



159 



a corresponding but greater one marks the opposite or neural surface, one process {hy, 

 fig. 18) descending, the other {ns) ascending. The neural spine gives off a pair of low 

 tuberosities, one on each side, near its summit : from each there is continued the usual 



FIFTEENTH VERTEBRA (I nat. size). 



Fig. 18. 



Fig. 19. 



Aspects. 

 Pig. 18, lateral; 19, hasmal (ventral). 



ridge curving back to the hyperapophysis (fig. 18, lip), which still overtops the post- 

 zygapophysis, ])Z. 



A mere rudiment of the interzygapophysial band now remains, but behind it is a 

 small foramen leading to the cancelli of the neurapophysis ; a corresponding foramen 

 is noticed in Stritthio ^. The pneumatic foramen is, as usual, beneath the base of the 

 diapophysis, which process shows its tuberous outstanding metapophysis (fig. 18, in), 

 well marked above the pleurapophysial band, ^j?. This, as in the seventeenth (last 

 cervical) vertebra in Struthio, is short antero-posteriorly, and each margin is concave, 

 with a blunt production of its hinder and lower angle still representing the cervical 

 riblet. Each vertebrarterial canal (figs. 20, 21, v), as in Struthio, exceeds the neural 

 canal in capacity. 



If the transverse expansion of the fore part of the centrum be reckoned as due to the 



' MiTart, he. cit. p. 409. 



