88 Prof. R. Owen on the Solitaire. 
There is one free-rib-bearing vertebra less, and one sternal 
rib less, than in Didus ; and this difference accords with the 
roportional larger trunk of the heavier Ground-Dove of the 
Tauritian Island. 
In the atlas and third vertebra the interzygapophysial bar, 
with the foramen it defines, is present*. The neural spine 
subsides to a pair of tuberosities in the fifth cervical; and this 
bifid condition is traceable to the ninth, where each division 
degenerates to the beginning of a ridge leading to the hypera- 
pophysis. ‘This process +, conspicuous and large on the axis 
and third vertebra, subsides in the following, but rises from 
its rudimental state in the ninth and following cervicals. 
The protuberance from the under part of the par-pleur- 
apophysis of the fifth and sixth cervicals shows as the “ cat- 
apophysis” of Mivart in the seventh; and, each converging 
towards its fellow, the pair of inferior processes become distinct 
in the ninth, approximate in the eleventh, and blend into the 
single median hypapophysis in the twelfth cervical vertebra. 
This process‘increases in vertical and fore-and-aft extent to the 
middle of the three coalesced dorsals, and almost disappears in 
the hindmost (fifth dorsal) ; it is similarly represented as a 
low median ridge in the last free dorsal (sixth). 
The sternum of Pezophaps, as of Didus, accords with the 
didunculine modification of the Dove’s breast-bone, in the 
breadth, for example, of the ectolateral processes and the 
absence of entolateral ones. The median hinder end of the 
sternum is narrower, more ‘ xiphoid”’ in character, than in 
Didunculus. The four articular ridges and depressions in 
each costal border are close-set, especially the third and 
fourth. 
The costal process is both broad and thick, presenting a 
trihedral subconcave facet towards the ribs. The thin ecto- 
lateral plate overlaps the two hinder hemapophyses joining 
the sternum.. The median pneumatic fossa at the anterior 
part of the sternal concavity communicates by a canal with 
the convex or outer surface. ‘The convex contour of the ster- 
nal keel is due to the suppression of the anterior subangular 
extension which is present in the volant Dodlet. 
The first and obvious character in which the great extinct 
Ground-Doves differ from the smaller existing volant kinds is 
in the small proportion of the brain-case to the rest of the 
skull. Ifthe length of the cranium be taken from the back 
of the occiput to the front of the frontal bone, it is, in Pezo- 
* “On Dinornis.—Pt. XXI.,” Trans. Zool. Soc. vol. x. p. 152, fig. 11, , s, 
third cervical of D. maximus. 
t Ihid. p. 151, fig. 4, hp. 
