PETERSON : A REVISION OF THE ENTELODONTID A 57 
second of the four premolars are separated by a diastema and have but a single ™ root 
the tubercles of the molars are low . . . the last molar two-lobed and rather 
small,” which should be regarded at least as of subgeneric value. Cope erected 
the genus Pelonax in 1874 (6, pp. 504-505) and said that it embraces species 
‘nearly allied to Hlotheriwm. It is more hippopotamoid than that genus [Archxo- 
theriwm] in the possession of four” digits on all the feet and a rudimentary fifth on 
the pes.” The statement regarding the digits of Cope’s genus Pelonaz is misleading, 
Tt 
La 
Type of Pelonax ramosum Cope. Cope Collection, No. 6393. About + nat. size. 
but the very large tuberosities on the chin and the single-rooted premolars, together 
with the characters enumerated above, are of considerable significance, and may 
be regarded as characterizing this subgenus. More material representing limbs and 
vertebree associated with jaws and skulls from the type locality is of extreme impor- 
tance in connection with the study of this subgenus. 
Pelonax bathrodon (Marsh). 
Type: Mz of right side. 
Horizon: Upper Oligocene. Protoceras Sandstones? 
16 
In a letter of reply from Dr. Matthew, of the American Museum of Natural History, New York, dated Feb. 26, 
1908, I am assured that Cope’s statement regarding the single-rooted premolars is correct. 
"No true Entelodonts from the Oligocene of America or Europe have as yet been found with four digits on all 
the feet, as in hippopotamus. 
