AXIAL SKELETON OF THE STRUTHIONID#. 31 
THE SACRAL VERTEBR. 
The thirty-seventh, -eighth, and -ninth vertebre, or sacral vertebre, must be so called 
because they seem to correspond in position with the sacral vertebre of the preceding 
genera. They cannot, however, be separated off from the vertebree which succeed them 
by any structural character, as can the vertebre of Struthio and Rhea—as they all, as 
in Dromeus, send out similar transverse processes to abut against the postacetabular 
part of the ilium. 
THE SACRO-CAUDAL VERTEBRA, 
The nine, ten, or eleven vertebree which succeed the sacral vertebre, 7. ¢. (in C. 
galeatus) the vertebrz from the fortieth to the fiftieth inclusive, are quite like those of 
Dromeus. They gradually elongate as we proceed postaxiad; and their transverse 
processes become successively wider axially. Their spinous process becomes successively 
shorter and more and more inclined postaxiad. 
THE CAUDAL VERTEBR. 
The eight or nine caudal vertebre (the jifty-first to the jfifty-ninth inclusive, in C. 
galeatus) closely resemble the caudal vertebre of Dromeus; but their transverse pro- 
cesses and their postzygapophyses are not quite so much developed ‘as in that genus. 
The pygostyle is like that of Dromeus, cylindrical and irregular, and looking as if made 
of three small vertebre ankylosed together (fig. 22). 
THE PELVIS. 
When viewed preazially the pelvis quite resembles that of Dromeus, except that 
(owing to the greater ventrad curvature of the postaxial part of the ilium) the ventral 
surface of the sacro-caudal vertebree comes more into view, and except also that the 
concavity between the antitrochanteric and supratrochanteric processes is as great as in 
Rhea. 
Viewed laterally, it only differs from that of Dromeus in that the dorsal margin of 
the postaxial part of the ilium is still more convex, in that the preacetabular part of 
the ilium is relatively greater, and in that the ischium and ilium may (as in C. galeatus) 
ankylose together at their distal ends. 
Viewed dorsally and ventrally, the pelvis shows no noteworthy differences from that 
of Dromeus, except that the inner surface of the ischium presents an antero-posterior 
groove. 
Tue Irom (figs. 22 & 26, i). 
The ilium extends over from about twenty-three to twenty-five vertebre, namely 
