400 MR. ST. GEORGE MIVART ON THE 
vertebra. It has here mounted more dorsally. The styliform rib-like process is rather 
longer in this fifth vertebra, but otherwise like that of the fourth. 
The metapophysis is rather more swollen and prominent; but the hyperapophysis is 
still more reduced. 
The prezygapophysis projects preaxially beyond the parapophysis to a less degree 
than is the case in the fourth vertebra. 
The neural spine is relatively less than that of the fourth vertebra, but otherwise 
resembles it, except that the two margins of the preaxial excavation do not stand out 
preaxially on processes with near so much distinctness. 
The neural arch when viewed from above is still less quadrate than in the fourth 
vertebra, because the transverse extent of the preaxial end of the fifth vertebra exceeds 
that of the postaxial part of the same vertebra more than the one exceeds the other in 
the fourth vertebra. 
The postaxial margin of the neural arch is also much more decidedly and sharply 
concaye. 
Tae SrxtH VERTEBRA. 
The sixth vertebra, though a larger bone than the fifth, resembles the latter in form 
and proportions, even more than the fifth vertebra resembles the fourth. Both the 
VENTRAL ASPECT OF SIXTH VERTEBRA (natural size). 
Fig. 25. 
Letters as in last figures, and in addition c, catapophysis. 
pre- and postaxial surfaces of the centrum agree with those of the fifth vertebra 
respectively ; and the neural surface only differs from that of its serial predecessor in 
being slightly more exposed preaxially. 
The ventral surface exhibits no noticeable differences, except that the hypapophysial 
ridge is still more obsolete, and that the postero-inner part of each parapophysis begins 
