1887.] -■ ^^ [Cope. 



sents the base ol the diapophysis. It is bifurcate for more than one-third 

 of its length at each end, the bounding walls embracing a deep conical 

 fossa. The walls of the centrum are thin, including a large central cavity. 



M. 

 Length of centrum of dorsal vertebra 043 



Diameters of posterior face -^ ^ r,Z. 



^ (.transverse 031 



Elevation of centrum to middle of diapophysis 023 



Transverse diameter of neural canal 006 



A caudal centrum is much elongate and has somewhat oblique articular 

 surfaces, though they are not so strongly so as in the case of the cervical 

 vertebra. The arch is lost from the specimen, so that nothing can be 

 said of the diapophyses. The articular surfaces are distinctly concave, 

 and the anterior is a little wider than deep, while the posterior is as wide 

 as deep. The middle of the centrum is depressed, giving a well-defined 

 inferior lateral longitudinal angle. There is also a low median inferior 

 angle, which gives way posterior to the two ridges that terminate in the 

 chevron facets, which are separated by a groove. 



M. 



Length of caudal centrum 051 



vertical 023 



Diameters posterior face i ^ noi 



(transverse 0-il 



Another caudal vertebra is much smaller, and has no chevron facets. 



It is more depressed than the larger one above described, and it has a 



wing-like lateral angle which connects the superior parts of the articular 



surfaces. Inferior surface flat, bounded on each side by a low angle. 



Neural arch distinct. It is a question whether this vertebra belongs to 



this species. It appears to me to be one of the terminal caudals. 



M. 



Length of centrum 035 



_. ^ . . (transverse 0105 



Diameters of posterior extremity -^ . , ^q^,- 



The ilitun consists almost exclusively of a frame for the large acetabu- 

 lum, and supports for the pubis and ischium. The anterior and posterior 

 extensions are insignificant. The anterior process is somewhat depressed ; 

 the posterior is compressed. The external border of the acetabulum is 

 produced, forming a roof, which is continued nearly to the articulation of 

 the pubic process, and which ceases at a greater distance above the articu- 

 lation with the ischium. The inner acetabular border is produced down- 

 wards, partially closing the acetabulum at its fundus. The pubic articu- 

 lar surface is rather larger than the ischiadic, and has a gently sigmoid 

 longitudinal section, the middle being concave. The pubic surface is on 

 the contrary gently convex in all directions, its outline being triangular. 

 The apex of the triangle is continued into the posterior border of the ace- 

 tabulum. The sacral or internal side of the ilium is flat. 



