414 MR. ST. GEORGE MIVART ON THE 
Excavations occur preaxially, as in the preceding vertebra; but postaxially they may 
exist close to the postaxial margin of the diapophysis, extending inwards to the base of 
the neural spine. 
The neural spine is more extended dorsally and slightly so antero-posteriorly ; its 
dorsal margin is rather convex, and bifurcates slightly at each end. That concavity 
which in the preceding vertebra exists on each side of the preaxial root of the neural 
spine is here deeper. 
The postaxial fossa is smaller; and the margins of the lamine which laterally bound 
it form rather less than a right angle with the postaxial margin of the neural spine. 
The zygapophysial articular surfaces are again slightly diminished. The twenty-first 
vertebra supports a long rib, which articulates by its distal end with the second 
sternal rib. 
Tur TWENTY-SECOND VERTEBRA. 
This vertebra is of about the same size as the twenty-first, in some respects less deve- 
loped, in others more so. 
Its centrum has its preaaial surface entirely occupied by the articular surface, and the 
ventral margins of both coincide, as there isno hypapophysial production. The surface 
is deeper dorso-ventrally, is less laterally produced, and may have its dorsal and ventral 
margins more concave and convex respectively. 
TWENTY-SECOND VERTEBRA (3 natural size). 
Fig. 50. Fig. 51. 
Fig. 49, lateral aspect; 50, dorsal aspect; 51, preaxial aspect. Letters as before, except v, excavation on 
preaxial side of diapophysis. 
Excavations are to be seen on the preaxial, postaxial, and ventral aspects of the diapophysis, the preaxial 
one being very much the larger. 
The postaxial surface of the centrum is rather larger and flatter, but very similar in 
figure to that of the twentieth vertebra; its dorsal margin, however, is rather wide and 
less concave. 
The neural surface of the centrum is more concave transversely at its preaxial part 
than in the vertebra last described. 
