EXPLANATION OF PLATE XXXL 



Figs. 1-3. Vertebra: of the LioHon di/upclor from Butte Creek, one-lialf uatural size. 



ri(i. 1. Atlas and axis from the front, the odontoid bono wanting: a, axis; b, neurapojihysis of atlas ; 

 c, basal element of atlas ; tl, hypapopliysis of the odontoid. 



2. Axis, posterior view. 



3. Third cervical vertebra, from boliind. 



4. Six caudal vertebrai of Ziodon dijajnlor, consecutive, except an interval between the third and 



fourth ; one-third natural size. Of the anterior three, the diapophyses of the left side aro 

 broken off, and the neural spines, being turned to that sideHjy jiressnre, arc displayed. From 

 the specimen figured in Plates xxvii-xxx. 

 T). Centrum of a lumbar vertebra of Liotlon dijupdor, from behind. From the type-specimen in tho 

 Muaeum of the Smithsonian Institution, from Fort Mi-Rae, New Mexico. 



