1883. ] Geology and Paleontology. 775 
orbit. The peculiar position of the teeth gives the side of the 
face, when the mandible is closed, a horizontally extended con- 
cavity. ` 
The dentition is remarkable for its complexity, and for the dif- 
ference in character presented by the superior and inferior series. 
Leidy pointed out the character of the latter! in the Hadrosaurus 
Soulkei, and I have described the character of the superior denti- 
tion in the genera Cionodon? and Diclonius? 
As compared with the Hadrosaurus foulkei, the dental maga- 
zine is much deeper, and contains a greater number of teeth in a 
vertical column, and probably a larger number in the aggregate. 
I find in each maxillary bone of the Diclonius mirabilis, six hun- 
dred and thirty teeth, and in each splenial bone, four hundred and 
six teeth. The total number is then two thousand and seventy- 
two 
The greater part of the external and inferior faces of the ramus 
of the lower jaw is formed by the surangular bone, which has 
in the fossil, in its present condition. This development and den- 
the Surangulars. The edge of the dentary is flat, thin and eden- 
tulous, and closes within the edge of the premaxillary. 
Vermal or corneous structures have left distinct traces in the 
_ Soft sandstone about the end of the beak-like muzzle. Lamine 
x brown remnants of organic structures were exposed in! re- 
: sends a median prolongation backwards, which is embraced by 
ie «Cretaceous Reptiles North America, 1864, p. 83. 
“Vertebrata of Cretaceous formations of the West, 1875, p. 59. 
__, Proceedings Philadelphia Academy, 1876, p. 250. 
Be: Bulletin Geological Survey of the Territories. F. V. Hayden, 11, pp. 594-7, 
