96 



observes of Diiioceras and the related Tinoccras, that they have the vertebral 

 and limb bones very similar to those of recent proboscideans, but refers them 

 to a new order vvitli the name of Dinocerea. 



The form of tlie thigh-bone and the short tarsal bones of Uintatherinm 

 \\ould appear to indicate limbs and feet most nearly constructed like those of 

 the elephant. I have provisionally placed the animal in the order of Probos- 

 cidea, leaving to Professor Marsh the determination of its true position from 

 the more abundant materials at his command. 



UlNTATHERIUM KOBUSTTIM. 



The remains which are specially to be regarded as characteristic of the 

 animal above named, and from which it was originally indicated, consist of a 

 mutilated cranium, to the matrix of which there adhere'd portions of both 

 jaws, containing all the last molars and an isolated molar. A nearly com- 

 plete humerus, together with some less well preserved specimens found in 

 association with the former, are supposed to have pertained to the same 

 individual. 



A small fragment of the upper jaw, containing the last molar tooth, is rep- 

 resented in Fig. 8, Plate XXV. The tooth, also represented in Figs. 6, 7, 

 of the same plate, and Fig. 30, Plate XXVII, has the crown composed 

 of a pair of wide pyramidal lobes projecting from a broad expanded base. 

 The lobes extend across the crown, conjoining internally and diverging ex- 

 ternally in a V-like manner. They project at their outer extremities in promi- 

 nent points, and also form together a prominent point at their conjunction 

 internally. The outer extremity of the anterior lobe is the most prominent 

 of the three points of the crown. The outer extremity of the posterior 

 Iol)e is the least prominent of the three points, while that at the conjunc- 

 tion of the lobes is scarcely more so. The acute summits of the lobes 

 between the points arc transversely concave, and are worn off on their anterior 

 slope so as to present narrow tracts of exposed dentine. The posterior slope 

 of the lobes is slightly concave ; and the valley between them is triangular, 

 and opens outwardly. 



From the posterior slope of the inner part of the back lobe of the crown 

 there projects a rounded tubercle about half-way between the basal ridge and 

 the pointed conjunction of the lobes. A second rounded tubercle occupies 

 the entrance of the triangular valley between the lobes. 



A stout basal ridge embraces the crown in front and behind, and in a 



