247 



HIPPARION. 



A small collection of fossils, submitted to my examination l)y Professor S. 

 B Buckley, mainly consist of equine remains, of wliich the determination is 

 uncertain and the near relations obscure. Most of them were obtained in 

 Washington County, Texas, a few in the contiguous county of Bastrop, and 

 several others in Navarro County. They were usually Ibund in digging wells, 

 at the depth of from 25 to 30 feet, imbedded in a rocky stratum. Most of 

 the specimens are free troui matrix, but several have attached portions of a 

 hard arenaceous limestone. From the character of the fossils, I suppose the 

 formation to be of contemporaneous age with that which has been called Plio- 

 cene Tertiary of the Niobrara River, Nebraska, Little White River, Dakota, 

 and that noticed in the preceding pages of the Sweetwater River, Wyoming. 



Fig. 14, Plate XX, represents a specimen labeled as having been obtained 

 from an ossiferous rock at a depth of 25 feet, in Washington County, Texas. 

 It is a last upper molar of a small equine animal, and is moderately worn' 

 away at the triturating surface. It is strongly curved, and is nearly twice the 

 length antero-externally that it is postero-internally. In the isolation of the 

 antero-internai column from the antero-median column, as seen on the triturat- 

 ing surface, it accords with the character of Hipparion. It sufficiently re- 

 sembles in its relative proportions, and the complexity of arrangement of its 

 enamel-folds, the fragment of a tooth, represented in Fig. 17, Plate XVIII, 

 of the Extinct Mammalian Fauna of Dakota, &c., to belong to the same species. 

 The latter specimen was also obtained in AVashington County, Texas, and has 

 been referred to Hipparion speciosum, a species originally proposed from 

 specimens discovered at Bijou Hill, Dakota, and represented in Figs. 1(1, LS 

 and 19 of the work just indicated. 



The measurements of the specimen are as follows: 



Lines. 



Length of crown anfero-externally H^ 



Length of crowu postero-internally ^h. 



Breadth of crown antei'o-posteriorly ^k 



Breadth of crown transversely - ^4 



Another specimen, consisting of the middle portion of an upper molar, from 

 its proportions and the folding of the enamel lakes of the triturating surfece, 

 is supposed to belong to the same species. It was obtained in Navarro 

 County, Texas. 



