THE DORSAL VERTEBRAE. 83 



Measurements of Second Dorsal Vertehra. {Dinoceras niirabile, No. 1255.) 



ni. 



Length of centrum, along floor of neural canal, 048 



Length of centrum, along under surface, ...__ .060 



Transverse diameter of anterior face of centrum, ._ .073 



Vertical diameter of anterior face of centrum, . . . . .075 



Transverse diameter of posterior face of centrum, .075 



Vertical diameter of posterior face of centrum, __. _. .070 



Transverse diameter of neural canal, . ._ .065 



Vertical diameter of neural canal, ... .057 



Diameters of anterior capitular face, 029-.033 



Diameters of posterior capitular face, .. J 9-.040 



Antero-posterior diameter of pedicel, _. .025 



Transverse diameter of pedicel, . ... .040 



Diameter of vertebra, across transverse processes, .200 



Diameter of vertebra, across post-zygapophyses, .. .080 



Least transverse diameter of neural spine, .035 



The Third Dorsal Vertebra. (Woodcaits 101 and 102, below.) 

 The third dorsal vertebra in the genera Dinocems and Tiiioceras differs 

 from the vertebra in front of it, in having the nenral spine less robust, and 

 the transverse processes, and the faces for the heads of the ribs on the 

 centrum, more elevated. The centrum itself is less e.xpanded transversely, 

 and its length is greater. 



Fig. 101. . Fig. 1C2. 



FiGPEE 101. — Third dorsal vertebra of Uiukitherium segne, Marsh (No. 1194); front view. 

 Figure 102. — The same vertebra; Hide view. 



d. transverse process; nc. neural caual ; r. face for head of rib; r'. face for tubercle of rib; s. neural 



spine. 



Both figures are one-fourth natural size. 



The third dorsal in Uintatherium segne (number 1194) shows 

 essentially the same characteristics, and is represented in tigures 101 and 

 102, above. 



