Cope.] ^44 [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- 

 ral arch. 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 

 zygapophyses are separated medially by a deep notch which extends to the 

 base 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 is a 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. 



f fore and aft 245 



Diameter of dorsal centrum 1 vertical 270 



(^ transverse 265 



