a 
Cope. | 244 {Dec. 21, 
portion of the centrum. Its inferior border is sunken abruptly, while the 
superior gradually shallows on the external surface of the base of the neu- 
ralarch. The foramen is longer than high, in contradistinction to that of 
the Camarasaurus supremus, where it is round or higher than long. 
The neural arch is very much elevated to the zygapophyses. It is 
strengthened by a prominent rib, which extends from the posterior base 
upwards and forwards to the base of the anterior zygapophysis. The sur- 
face above and behind this is occupied by an extensive excavation whose 
superior border is the line connecting the zygapophyses. The anterior 
zy gapophyses are separated medially by a deep notch which extends to the 
hase of the neural spine. The articular surfaces incline towards each 
other. Just behind the anterior zygapophysis, a process extends outwards 
and forwards whose extremity is lost in my specimen. Its posterior face 
is excavated by the lateral fossa above described. This process is probably 
the diapophysis which supports the rib. The diapophysis springs from the 
line connecting the zygapophyses, and extends upwards and outwards. Its 
inferior surface is deeply excavated. Its anterior border sends a lamina 
upwards, which probably reached the side of the neural spine, but is broken 
off in my specimen. 
The neural spine is thin, but its anterior and posterior borders are thick- 
ened and double, the lateral rib-like edges being separated by grooves 
which expand at the base. The posterior groove continues to a more ele- 
vated point than the posterior. Each side of the spine is divided into two 
shallow wide grooves by a median keel. The apex of the spine is much 
thickened transversely, its obtuse extremity having the fore and aft and 
transverse diameters equal. 
The pubic bone resembles that of the Camarasaurus supremus, but is 
less robust in all its parts. It is also less extended in antero-posterior width 
near the proximal extremity. 
The femur is remarkable for its slender form. It isa few inches longer 
than that of the Camarasaurus supremus, but is not so robust. The shaft 
is nearly round and somewhat contracted at the middle, where it is slightly 
convex backwards. It is slightly curved inwards at the great trochanter. 
Here the shaft is moderately grooved on the posterior face. This trochan- 
ter is only a prominent ledge below the head. The third trochanter is sit- 
uated a little above the middle of the shaft; it is a prominent obtuse ridge 
directed backwards. The condyles are extended well posteriorly, and are 
separated by a deep popliteal groove, which originates on the inferior por- 
tion of the shaft. They are also separated anteriorly by a shallow open 
groove. The external condyle is rather more robust than the internal. 
The length of the femur is six feet four inches ; the elevation of the 
dorsal vertebra three feet three inches. 
Measurements. M. 
; ( Fone MN Gyailtscr ecient ae 245 
Diameter of dorsal centrum 4 vertical ........... ate 270 
