CHAPTER 11. 



THE VERTEBRATE FAUNA OF THE LOUP FORK BEDS, 



Abundant remains of Vertebrata were found in the Loup Fork beds 

 north of the South Fork of Red River, east of the eastern escarpment 

 of the Staked Plains. With the exception of a tortoise, these belong 

 exclusively to Mammalia of the superorder Ungulata. The extreme 

 rarity of Carnivora and the absence of Glires, are noteworthy features 

 of the localities examined. Of seventeen species obtained, fifteen are 

 determinable, as follows: 



Species, Determinable. 



Testudinata 1 



Carnivora 1 



Proboscidia 1 1 



Diplarthra — 



PerLssodactyla 9 9 



Artiodactyla 5 3 



17 13 



Of the determinable species, two are new to science. All the others 

 are species hitherto found only in beds of the Loup Fork terrane, thus 

 fixing conclusively the age of the Texas bed. Much light is thrown on 

 the structure of many of these species by the new material obtained which 

 is now described in part. 



It is evident that the locality at which the fossils were obtained was 

 haunted by droves of three-toed horses and camels, with not a few mas- 

 todons. At one place a space of several acres was thickly strewn with 

 bones of these animals; and smaller tracts similarly covered were numer- 

 ous in the same neighborhood. The animals were of all ages, and one of 

 the most interesting results of our expedition was the obtaining of the 

 bones, skulls, and teeth of young animals with the deciduous dentition 

 well preserved. 



PROBOSCIDIA. 

 TETRABELODON, Cope. 



Proceeds. Amer. Philos. Society, 1884, p. 2. 

 American Naturalist, 1889, p. 193. 



TETRABELODON SERRIDENS ? Cope. 



American Naturalist, 1889, p. 205, figure 8; Mastodon serridens, Cope, 

 1. c. 1884, p. 524; Plate III, figures 2, 3. 



