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DEC 5 W» R. 



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PALjflONTOL OICAL B ULLETIN. 



IsTO. 17. 



FOURTH NOTICE OF EXTINCT VERTEBRATA FROM THE 

 BRIDGER AND THE GREEN RIVER TERTIARIES. 



By Edward D. Cope, A.M. 



EOBASILEUS GALEATUS. Sp. nOV. 



Represented by the greater portion of a cranium of an individual of 

 the size of the Loxolophodon cornutus. It possesses a greatly elevated 

 occipital crest, whose superior border presents a median angle upwards. 

 A short distance in front of it and connected by a very stout lateral ridge, 

 there arises on each side a large erect horn-core. The base is very 

 massive, subquadrate in section, and flattened in front. Posteriorly it 

 presents a very shallow groove, which is bounded on the outer side by a 

 low ridge. The shaft expands gradually and is proportionally flattened 

 from behind forwards. The posterior face is flat, the anterior gently 

 convex. The extremity is transverse convex, and fitted for cartilaginous 

 or corneous attachment. These horns stand on the parietal bones. The 

 frontals extend to their bases, and send a laminar expansion back- 

 wards to the margins of the lateral and posterior crests, covering the 

 parietal in the fundus of the basin which the former enclose.* 



The median horns are very stout, and are connected with the posterior 

 by an acute supratemporal ridge. Their inner face is composed to near 

 the apex by the nasal bones. Where they terminate, the apex contracts, 

 and is composed of a cylindric production from the maxillary. The 

 section of these cores at the middle is subquadrangular, and longitudin- 

 ally oval at base. 



The extremity of the nasal bones is small and contracted, and is ex- 

 tensively overhung by the cornice-like flat cores above them. Thus the 

 end of the snout has a bilobate outline when viewed from above. 



The occipital face is concave in vertical section and presents a V-shaped 

 depression with the angle downwards, and a low ridge on the middle line 

 to the transverse superior border. 



Measurements. M. 



Width of the foramen magnum and occipital condyles. .2100 



Elevation of occiput (eight in.) 2500 



Width of basin between lateral crests 3250 



Height of posterior horn-core (seven in.) 2300 



Width base do. antero-posteriorly 1300 



" " transversely 0900 



" of summit 1230 



Height of median horn-core 1750 



* Marsh, originally stated that these horn-cores in Uintatherixim rnirabile stand on the 

 frontal ; but later that it was doubtful whether the frontal supported horns. 



