106 31. R. Thorpe — John Day Eporeodons 



3l€asi(rements of Holoti/pe. 



mm. 



Total length of sknll 208 



Bizygomatic diameter 121.6 



Superior molar series, length 42.3 



Superior premolar series, length 40 



Diameter, postorbital constriction 36.5 



Eporeodon perhullatus, sp. no v. 



(Figs. 9, 10.) 



Holotvpe, Cat. Xo. 11011, Y, P. M. Upper Oligoeeue (upper John Day), 

 Bridge Creek, John Day Eiver, Oregon. Collected by S. H. Snook in 1874. 

 Paratypes, Cat. Xos. 12319 and 12320, Y. P. M., Upper Oligocene (middle 

 John Day), also from Bridge Creek. Collected by L. S. Davis in 1874. 



Specific characters. — Bulla} relatively enormous, full 

 and ovate and nearly twice the size of those in E. Jepta- 

 canthus, which is the largest species of this genus in the 

 John Day basin ; lacrymal fossae deep and large ; para- 



7Wn, TYPE 



Y. P. M. 



Fig. 9. — Eporeodon perhuUatus, sp. nov. Holotvpe. Left lateral view. 

 X 2/5. 



mastoids transversely compressed, ending inferiorly in a 

 thin tip and they extend downward and well ouhvard 

 from the median line of the bullae ; postgienoid tubercles 

 relatively small; length of superior dental series inter- 

 mediate between E. pacificus and E. lept acanthus; nasal 

 bones wide; cranium wider than in E. leptacanthus; 

 palate produced but a very short distance beyond last 

 molar; masseteric fossa relatively deep. 



