AXIAL SKELETON OF THE OSTRICH. 429 
Tue Forty-EIGHTH VERTEBRA. 
This vertebra is like the last, except that there are no snbcentral excavations. The 
diapophyses extend less dorsad ; and the parapophysial projection is smaller on each side. 
Tue Forty-NintH VERTEBRA. 
This vertebra differs from the preceding chiefly in the sudden reappearance of a 
parapophysis of considerable size. It is, however, continuous with the diapophyses, 
the two appearing as a transyerse process, which projects outwards and slightly post- 
axiad from the postaxial part of the side of the centrum, and expands dorso-ventrally 
towards its distal end (fig. 65, d, p). 
THE FORTY-NINTH, or THIRD CAUDAL VERTEBRA (natural size). 
Fig. 65. 
Fig. 65, preaxial aspect. Letters as before, except that ¢ denotes the “transverse process,” which probably 
contains both a diapophysial (d), and a parapophysial (p) element. 
Its free cuter margin is dorso-ventrally concave, the prominence at the dorsal side of 
the concavity representing the rounded end of the diapophysis, while the sometimes 
less marked prominence on the ventral side of the concavity represents the rounded end 
of the parapophysis. ‘The preaxial surface of the transverse process is excavated and 
dorso-ventrally concave. 
Tue FirtierH VERTEBRA. 
The fiftieth vertebra is slightly smaller than the forty-ninth, which it greatly resembles, 
except that the parapophysial (ventral) extremity of the transverse process is decidedly 
more produced than the diapophysial one. 
The neural canal is also smaller, and the lateral summits of the laterally bifurcating 
neural spine more divergent. 
Tue Firry-rirst VERTEBRA. 
Here we find an intensification of the differences noticed in describing the fiftieth 
vertebra ; and the outer margin of the centrum also more nearly approaches a circle. 
The preaxial surface of the centrum is decidedly concave. 
