402 MR. ST. GEORGE MIVART ON THE 
The interval between the pre- and postaxial excavations of the neural spine pro- 
gressively 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. VENTRAL ASPECT OF EIGHTH VERTEBRA. 
Immature condition (natural size). Immature condition (natural size). 
Fig. 26. Fig. 27. 
The rib-like part, ps, is removed on the left side ; Letters as before, except i, catapophysis, and 
d, diapophysis. 7”, parapophysis. 
NINTH VERTEBRA (size 3 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 postaxia] end of the postzygapophysis. This vertebra, however, is very 
slightly more massive than the preceding one. 
