OREODOimDJE. MERYCOPOTAMIDJi:. 209 



Eporeodon major (Leidy 1 ). 



Syn. Oreodon major, Leidy 2 . 

 Euerotaplius major, Cope 3 . 



Hah. N". America. 



40342. Cast of the cranium, wanting the crowns of the anterior 

 teeth. The original is from the Miocene of the White 

 River, Dakota, U.S.A. ; and is figured by Leidy in the 

 Journ. Ac. Nat. Sci. Philad. vol. vii. pi. viii. 



Purchased, 1867. 



29680. The middle portion of the cranium and mandible, showing 

 nearly all the cheek-teeth, in an early stage of wear ; from 

 the Miocene of the White River. Purchased, 1855. 



Family M^ERYCOPOTAMID^E. 



Dentition : — I. |, C. \, Pm. |, M. |. The upper true molars are 

 selenodont, and have four columns on the masticating surface ; in 

 other respects those of the type genus are very like the molars of 

 the hypsodont species of Hyopotamus. Both genera are referred by 

 Flower to the Anthracother 



Genus MERYCOPOTAMUS, Falconer and Cautley 4 . 



The mandible has a deep descending process at the angle, as in 

 Hippopotamus', the canines are very large and pig-like, but the 

 extremity of the upper one is not recurved upwards. 



Merycopotamus dissimilis, Falconer and Cautley 5 . 

 Syn. Hippopotamus dissimilis, Falconer and Cautley 6 . 



This species is considerably larger than the next, and is also 

 distinguished by the wider mandibular symphysis, the much longer 

 jaws, the straighter cranial profile, the presence of a deep fossa on 

 the outer side of the mandible behind the canine, and the nearly flat 

 inner surface of the third lobe of the last lower true molar. A right 



i » j 



1 Smith. Contrib. to Knowl. vol. vi. art. 7, p. 55 (1854). 



2 Loc. cit. 



3 Proc. Amer. Phil. Soc. vol. xxi. p. 519 (1884). 



4 In Owen's ' Odontography,' p. 566 (1840-45). 



5 ' Asiatic Researches,' vol. xix. p. 51 (1836), Hippopotamus. 



6 Loc. cit. 



PART II. P 



