muzzle. These diverge outwards, the outer sides being flattened and 

 the summits contracted aiid truncate. They are mere rudiments of the 

 horns seen in M. aceronsor, M. color adoensis. The molar teeth do not 

 exhibit the T-shaped cross-ridges seen in Miobasileus, and the two outer 

 crescents are continuous with each other. 



Measurements. 



M. 

 Length from posterior rim of temporal fossa to middle 



of osseous eyebrow 472 



Least width of parietal plane 104 



Superciliary width 260 



Elevation of horn-core 050 



The premaxillary region of this specimen was destroyed, so that no 

 account of the anterior dentition can be given. 



Of the horned Perissodactyla four species are described above, but 

 there is little doubt that they represent but three. The lower jaws of 

 the genus Symborodon pertain to the cranium of one of the species re- 

 ferred to Miobasileus or Megaceratops, but to which, it is impossible to 

 state at the present time. Opportunity for solving this point will no 

 doubt soon occur. All of these species are abundantly distinct from the 

 Megaceratops coloradoensis, Leidy. Known from a fragment of the snout. 

 As to the generic distinctness of the two genera here proposed, it is 

 obvious that Miobasileus is distinct from Megaceratops, but whether Sym- 

 borodon be so, is not determinable. Until the dentition of that form be 

 known, its relations both to Symborodon and Brontotherium will remain 

 in uncertainty. 



The two genera of the formation in question correspond with those 

 described last summer from the older period, thus : 

 Horn over orbit, 



Miobasileus. Loxolopliodon. 



Horn anterior to orbit, 



Megaceratops. Uintatherium. 



Reptilia. 

 Peltosatjrus granulosus. Gen. et sp. nov. 



Order Lacertilia. Premaxillary undivided, with spine ; a parietal fon- 

 tanelle and parieto-quadrate arches. Teeth pleurodont, with obtuse 

 compressed crowns, of similar form on all the jaw bones. Body covered 

 with osseous scuta, which are in places united by suture. Vertebras de- 

 pressed, with simple articulations. Median hexagonal dermal scuta on 

 the parietal bone. Parietal united. 



Char, specif. Parietal bone broad and flat, frontal little narrowed, 

 gently convex, both with finely granular upper surface. Scuta not 

 keeled, finely granular. Number of teeth on premaxillary bone seven ; 

 teeth on dentary ten in M. 010. Surfaces of dentary smooth. 



