428 MR. ST. GEORGE MIVART ON THE 
THE CAUDAL VERTEBRZ. 
Tue Forty-seveNtH VERTEBRA. 
This vertebra remains normally unanchylosed with the preceding bone in the adult 
bird. 
It has a massive centrum and a neural arch small in circuit and very little developed 
antero-posteriorly, with a wide and massive neural spine and a moderate transverse 
process. 
The centrum has its postavial surface nearly flat or slightly concave or convex. 
Its dorsal margin is slightly concave, its ventral margin very slightly convex. 
The preavial surface of its centrum is slightly concave, and its ventral margin nearly 
straight. 
THE FORTY-SEVENTH, on FIRST CAUDAL VERTEBRA (natural size). 
Fig. 63. 
ae 
Fig. 63, preaxial aspect; 64, lateral aspect (left side). Letters as before. 
The ventral surface of the centrum shows the subparallel antero-posterior excavations 
separated by a considerable interval. The excavations, however, are less extensive than 
are those in more preaxial vertebre. 
The diapophysis (figs, 63 & 64, d) projects dorsad, outwards and very slightly post- 
axiad; it is subconical, rather flattened pre- and postaxially, and with a somewhat 
rounded extremity. A very small parapophysial process projects from or ventrad of 
the ventral side of its root, extending slightly outwards from the lateral margin of the 
ventral surface of the centrum at or postaxiad of the antero-posterior middle point of 
that margin (figs. 63 & 64, p). 
The neural lamina of each side has its postaxial margin nearly vertical; but its pre- 
axial margin is inclined preaxiad and dorsad. 
The neural spine is much more developed transversely than antero-posteriorly, and 
shows a tendency to bifurcate, its lateral extremities extending more or less outwards 
and preaxially. 
There are no zygapophyses. 
