260 



posed lo belong to a species of Procamelus. The specimens, consisting of a 

 last premolar, and the first and last molars of the lower jaw, are represented 

 in Figs. 26 to 29, Plate XXVII. The teeth have the same form and consti- 

 tution as those of the western species of Procamelus above named, and they 

 appear to indicate an additional species, which was about the size of the ex- 

 isting llama, and intermediate in size to P. occidental if and P. gracilis 

 The measurements of the teeth are as follows : 



Lines. 



Anteroposterior diameter of last premolar 7 



Transverse diameter of last premolar 4 



Anteroposterior diameter of first molar 7-j| 



Transverse diameter of first molar G 



Anteroposterior diameter of last molar 12£ 



Transverse diameter of last molar 



MEGALOMERYX. 



Megalomeryx niobrarensis (?) 



The genus to which the above name was applied, has not been determined 

 by positive characters, and may prove not to be distinct from Procamelus. 

 It was proposed on two specimens of teeth of a large ruminant, apparently 

 of the camel family, discovered by Professor Hay den in the Pliocene Tertiary 

 sands of the Niobrara River, Nebraska. The teeth, both lower molars, are 

 described in the " Extinct Mammalia of Dakota and Nebraska,'' page 161, and 

 are represented in Figs. 12-14, Plate XIV, of that work. 



A similar tooth was submitted to my examination, by Professor J. D. Whit- 

 ney, from the Pliocene Tertiary of Tuolumne County, California. 



Figs. 24, 25, Plate XXVII, represent a mutilated lower molar, apparently 

 of the same species. This was found in L'Eau qui Court County, in Northern 

 Nebraska, and was presented to Swarthmore College by George S. Truman. 



CHELONIA. 



EMYS. 



Emys petrolei. 



An extinct species thus named is indicated by a number of fragments of 

 several turtle-shells, which were found in association with remains of Masto- 

 don, Megalonyx, Equus, Trucifelis fatalis, &c, in Hardin County, Texas. 

 They were obtained from a stratum of clay beneath a bed of bitumen, and, 



