95 



genus with the names of Dinoceras mirabilis and D. lacustris. Of the skull 

 of this genus, he observes that it presents a most remarkable combination of 

 characters. "It is wedge-shaped, elongated, and quite narrow, especially in 

 front, and was armed with horns and huge decurved canine tusks. The top 

 of the skull, moreover, is deeply' concave, and has around its lateral and pos- 

 terior margins an enormous crest. On the frontal bones, above the orbits, 

 and in advance of the lateral crest, there is a pair of very large horn-cones, 

 just behind and above the canines. These are directed upward and outward, 

 and their summits are obtuse and nearly round. They are solid, except at 

 the base, which is perforated by the upper extremity of the canine. Near 

 the anterior margin of the nasals there is still another pair of horn-cones, 

 which are near together, and have obliquely compressed summits. The nasal 

 opening is small. The premaxillaries are slender and without teeth. The 

 upper canines are greatly elongated, slightly curved, and compressed longi- 

 tudinally. The lower portion is thin and trenchant. Behind the canine is a 

 long diastema, followed by a series of six small teeth. The molars have their 

 crowns composed of two transverse ridges, separated externally, and meeting 

 at the inner extremities. The skull measures about 28 J inches long and 8£ 

 Inches in width over the orbits. The canine is 9| inches in length below 

 the jaw, 64 millimeters in longitudinal diameter at base, and 25 millimeters 

 in transverse diameter. The last upper molar lias an antero-posterior diameter 

 of 36 millimeters." 



It appears to me that the brief description of the skull and molar teeth of 

 Dinoceras applies so closely to the corresponding parts of Uintatherium as 

 to render it probable they are of the same genus. The description of the 

 tusks of the former also equally well apply to those of Uintamastix, so as to 

 lead me to suspect that this may likewise be the same as Uintatherium. It 

 is probable, too, that should the latter not be the same as Dinoceras it may 

 prove to be the same as Tinoceras, or perhaps the Eobasileus s. Loxolophodon 

 of Professor Cope. 



The characters of Uintatherium, as expressed in the material at our com- 

 mand, are so peculiar and unlike those of any other known animal as to ren- 

 der its ordinal affinities obscure. From the form and constitution of the 

 molar teeth alone, I should have viewed the genus as pertaining to the odd- 

 toed pachyderms. If the remains noticed by Professor Marsh under the 

 name of Dinoceras belong to the same animal, the presence of horns in pairs 

 1o the head would render such a reference improbable. Professor Marsh 



