!>1 



east of" our camp, Ur. Corson culled my attention to a large tusk which he had 

 found mingled with some drift-pebbles that had fallen from the top of the 

 buttc. In the tusk I thought I recognized the canine of a Large carnivore 

 related to the extinct saber-toothed tiger of Brazil. On further search, we 

 found a portion of the opposite tusk, an isolated molar supposed to belong to 

 Uintatherium, another of Palaeosyops, and the scale of a ganoid fish. 



In the same letter above mentioned, the large tusks were described and 

 attributed to a carnivore with the name of TJintamastix atrox. 



On our return to Fort Bridger, while examining and discussing the fossils 

 collected in our expedition, the question arose whether the large tusks did not 

 pertain to the same animal I have named Uintatherium. Our specimen of 

 the skull of the latter did not assist the determination of the question, as the 

 facial portion was wanting, excepting small fragments of the back of the jaws 

 containing the last molar teeth. While admitting the probability of the tusks 

 pettaining to Uintatherium, from their being so unlike those of any known 

 pachyderm, and from their near resemblance, both in form and size, to those 

 of the great extinct Machairodus of Brazil, I thought the weight of evidence 

 was in favor of their reference to a carnivore. The finding of a molar tooth 

 of Uintatherium in association with the tusks appeared to me not to outweigh 

 this evidence any more than the association with them of a molar of Palaeo- 

 syops. 



Professor Marsh has published several notices in the American Journal of 

 Science of the remains of large mammals from the Bridger Tertiary forma- 

 tion, which appear to be related with Uintatherium. 



In June, 1871, he reported the discovery of bones of a large animal which 

 he referred with doubt to Titanotherium, with the name of T. anceps. From 

 some additional remains, in a foot-note of July 22, 1072, he refers them to a 

 proboscidean under the name of Mastodon anceps. This is corrected in an 

 erratum of August 19, referring the animal to a new genus with the name 

 of Tinoceras anceps. September" 21, he published a notice of a new species 

 with the name of Tinoceras grandis, founded on portions of a skull and teeth, 

 &c. Of this he observes, " The skull is proportionately very small, and indi- 

 cates one of the most remarkable animals yet discovered. It supports a pair 

 of short horns, and has also two powerful tusks, which, in size, shape, and 

 direction, resemble the canines of the walrus." 



More recently, September 27, Professor Marsh has published a "notice of^ 

 some remarkable fossil mammals," which are referred to two species of a new 



