Peterson : A New Titanothere from the Uinta Eocene. 51 



estimated diameters and are consequently conjectural as to proper 

 contour outlines. This is especially true of the posterior portion of 

 the skull, the sacrum, the ischium, the upper half of the femur, and 

 the caudal region. There are inserted two cervicals, two dorsals, the 

 sacrum, and the greater part of the caudal region. The vertebral 

 formula as represented in the illustration is the same as that of the 

 articulated skeleton of Titanotherium from the Oligocene now in the 

 Carnegie Museum. The vertebral formula of Diploceras osborni is 

 in part therefore tentative and is as follows: Cervicals seven, dorsals 

 seventeen, lumbars three, sacrals four, caudals eighteen. The ribs 

 are conjectural. 



The illustra ion is effected for the purpose of ascei taining, at a 

 glance, the general proportions of the animal. Each part represented 

 by the solid lines h drawn directly from the bones themselves, by the 

 assistance of the pantograph, and the illustration as a whole is fairly 

 reliable. 



M EASUP.EMENTS. 



Cm. 

 Total length of the vertebral column from the premaxillary to the end of 



the sacrum, all curves of the backbone included 252 



Height of skeleton at fore limb 138 



Height of skeleton at hind limb 114 



Taxonomic Position of Diploceras osborni. 

 From the foregoing introduction and description it appears that 

 Diploceras osborni should be placed in a phylum leading to the long- 

 limbed animals of the Oligocene, which Osborn lefers to typical 

 Titanotherium Leidy.^^ Moreover, we are now more certain that true 

 horned forms of this family weie already well established in hoiizon 

 B, and possibly also in the preceding horizon A of the Uinta Eocene 

 formation. As had been anticipated by some and conclusively shown 

 by Osborn and stafif^' the Washakie and the Uinta sediments were 

 formed contemporaneously. No remains of these true horned types 

 have as yet been found in the upper Washakie sediment, though they 

 undoubtedly existed at that time. Characters of the foot-structure 

 available for comparison, show that Diploceras of the Uinta R is quite 

 similar to Mesatirhinus from the base of the Washakie, namely, the 

 astragalus with neck elongated, ectal and cuboidal facets continuous, 



18 Bull. Amer. Mus. Nat. Hist., Vol. XXIV. 1908, p. 611-613. 

 1' Bull. Amer. Mus., Vol. XVI, 1902, p. 92. 



