62 



proper positions and the neiiral spines, whose bases are well j^reserved, are indicated, by- 

 dotted lines, of a length equal to ihat of a spine of a second sacrum of this species, mea- 

 sured in the field. The diapophyses are apparently not long* enough to effect a union 



Fig. 17. — The same sacrum ; right lateral aspevt; about one-seventh the natural size, a, a, facet for ilium; cZ, diapo- 

 physis ; up. neural platform ; us, neural spine ; ;', interspace. 



with the ilium. It is possible that the concave part of the iliac facet entered into the forma- 

 tion of the acetabulum. The articular face of the first vertebra is slightly broader than 

 high but in the face of the last vertebra the excess of breadth over the height is much 

 more apparent; the anterior vertebral face is plane, the posterior one is flat vertically 

 but concave transversely. Viewed from the side, the sacrum is moderately arched above 

 but flat below. 



Measurements of sacrum. 



Extreme lenght of sacrum (30| inches) . 



Basal length of 1st vertebra 



" " 2ud " 



" " 3rd " 



" 4^1 " 



" "5th " 



" 6th " 



" 7th " 



" 8th " 



" 9th " 



Height of articular face of 1st vertebra. 



Breadth of s^auie 



Height of articular face of 9th vertebra 

 Breadth of same 



M. 



766 



084 



102 



085 



092 



086 



088 



088 



078 



063 



110 



123 



108 



150 



* The apparant shortness of the diapophyses may be due in a great measure to the downward crushing to which the 

 specimen has been subjected. 



