402 



MR. ST. GEOEaE MIVAET OX THE 



The interval between the pre- and postaxial excavations of the neural spine pro- 

 a;ressively increases. 



In the tenth vertebra the transverse dimension of the postaxial part of the neural 

 arch (measured from outer margin to outer margin of the two postzygapophyses) 

 begins to be slightly less in defect compared with the same dimension of the preaxial 

 part of that arch. 



PREAXIAL ASPECT OF EIGHTH VERTEBRA. 

 Immature condition (natural size). 

 Fig. 26. 



VEXTRAL ASPECT OF EIGHTH VERTEBRA. 



Immature condition (natural size). 

 Fig. 27. 



The rib-like part, ps, is removed on the left side ; 

 d, diapophysis. 



Letters as before, except Ic, catapophysis, and 

 r, parapophysis. 



XINTH VERTEBRA (size -| of nature). 

 Fig. 28. 



Dorsal aspect. Letters as before. 



In the tenth vertebra also the prezygapophysis projects about as far preaxially as 

 does the parapophysis. 



The Eleventh Vertebra. 

 The eleventh vertebra is of very nearly the same length as the tenth, especially as 

 estimated by the antero-posterior extent between the preaxial end of the prezygapo- 

 physis and the postaxial end of the postzygapophysis. This vertebra, however, is very 

 slightly more massive than the preceding one. 



