142 PROCEEDINGS OF THE NATIONAL MUSEUM vol. los 



state of preservation. Judging from the dimensions of the centrum 

 and the shape of the neural spine, it seems to be the sixth in this 

 series. 



The lateral surfaces of the centrum (pi. 15, fig. 6) are depressed 

 above and below the transverse processes. The convex anterior and 

 posterior surfaces of the centrum appear to have been of nearly equal 

 width. Between the anterior and posterior descending processes 

 the ventral surface of the centrum is deeply depressed and two small 

 foramina are located near the middle of this ventral groove. The 

 posterior facets for the chevron bones are placed obliquely on the 

 posterior surfaces of the large descending processes, but unfortunately 

 the surfaces where the anterior facets were located are eroded. 



The right transverse process was broad (36 mm.) at the base and 

 the basal foramen is minute; the corresponding foramen on the left 

 transverse process is normal in size. The pedicles of the neural arch 

 are relatively broad (minimum anteroposterior diameter of right, 

 31.5 mm.) in comparison to the length of the centrum (58 mm.), and 

 the neural spine is slightly wider near its base than the pedicle. 

 The narrow neural canal measures 14 mm. in height anteriorly. 



Measurements of vertebhae (in millimeters) 



Greatest anteroposterior diameter of centrum 



Greatest vertical diameter of centrum anteriorly 



Greatest transverse diameter of centrum anteriorly 



Greatest vertical diameter of neural canal anteriorly 



Greatest transverse diameter of neural canal an- 

 teriorly 19.0 23.0 4.0 



Least anteroposterior diameter of pedicle of neural 



arch 16.0 21.0 29.0 



Distance across vertebra between outer ends of 



diapophyses 68. 



Distance across vertebra between outer ends of 



transverse processes 75. 5 71.+ 



Greatest distance between outer margins of pre- 



zygapophysial facets 28. 



Greatest distance between outer margins of post- 



zygapophysial facets 28. 



RIB 



The neck of the first rib on the left side is flattened, relatively deep, 

 and bears an elongated or ovoidal capitular facet at the extremity. 

 The larger tubercular facet is also elongated and is subtriangular in 

 outline. The rather wide and flattened shaft terminates in a slightly 

 thickened distal end. Between the tuberculum and the angle the 

 widened dorsal edge of the shaft slopes obliquely from posterior to 



