AXIAL SKELETON OF THE STEUTHIONID.^. 37 



postaxial to the fifth, and from the penultimate cemcal of all the other Struthionidse 

 by its very prolonged neural spine, which presents such a contrast to that of its preaxial 

 predecessor. 



FOUR VERTEBRA OF APTERYX (twice the natural size). 



Fig. .37. 



Fig. 39. 



Fig. 37. Lateral view of seventh vertebra. 

 Fig. 39. Ventral view of ninth vertebra. 



Fig. 38. Postaxial view of eighth vertebra. 

 Fig. 40. Preaxial view of eleventh vertebra. 



e, Catapophysis ; d, diapophysis ; /, lateral forameu ; Ay;, hyperapophysis ; ns, Deural spine ; p, parapophysis ; pi, styloid rib : 



as, praizygapophysis ; pz, postzygapopbysis. 



In the fifteenth vertebra the neural spine is slightly higher. The diapophyses are 

 still largely developed, and appear even longer than the parapophyses with their anky- 

 losed pleural elements, which, however, appear to be mutilated in the specimens 

 examined. 



THE CERVICO-DORSAL VERTEBRA. 



This vertebra has an elongated neural spine of the same length as that of the last 

 cervical vertebra. Its diapophysis is much axially extended ; and it bears a single hypa- 

 pophysis, the development of which in A. australis is still equal to that of any pre- 

 ceding vertebra. 



