252 



' Ml 



The teeth in the specimens, as represented in Figs. 16, 17, Plate VII, arc 



considerably worn, bul retain their anatomical characters sufficiently to show 



thai they are identical in form with those of the two species just named. 



They nearly accord in size with the mutilated upper molar, represented in 



Fig 5, Plate II, from Oregon, referred to Anchitherium Condon). In the doubt 



whether the latter is really a true species of the genus in which it has been 



placed, the lower-jaw fragments in question are regarded as representing a 



species with the name heading the chapter. 



Measurements from the specimens are as follows: 



Lines. 



Space occupied by the back lour molars 34 



Space occupied by the back three molars 27 



Fore and aft diameter of last premolar .... S 



Transverse diameter of last premolar (;a 



Fore and aft diameter of first molar ... T\ 



Transverse diameter of first molar 7 



Fore and aft diameter of last molar 11 



Transverse diameter of last molar h\ 



Anchitherium (?) . 



In digging a w r ell at Antelope, Nebraska, in the summer of 1868, at the 

 depth of 60 feet a stratum was found which was stated to be remarkable 

 for the number of fossil-bones it contained. The relative age of the stratum 

 has not yet been ascertained, but from the character of the fossils it is sus- 

 pected to be contemporary with the Mauvaises Terres formation of White 

 River, Dakota, or perhaps with the later formation of the Niobrara River, 

 Nebraska. From among the specimens collected at the time, my friend Dr. 

 John L. Le Conte obtained a coronary bone of a small equine animal, which he 

 sent to me for examination . 



The specimen was exhibited to the Academy of Natural Sciences, and is 

 noticed in its Proceedings for August, 1868. Subsequently, some remains, 

 apparently of the same animal, from the same locality were described by 

 Professor Marsh in the American Journal of Sciences for October, 1868, and 

 referred by him to a diminutive horse with the name of Equus parvulus. 



The specimen of the coronary bone is represented in Fig. 23, Plate XX. 

 It is only a little over half the length and is considerably less than half the 

 breadth of the corresponding bone of the horse, so that it indicates an animal 

 of little more than half its height and of more slender proportions. Its 

 size would about accord with Anchitherium Bairdi of the White River 

 Tertiary formation of Dakota. 



