F. B. Loomis^New Genus of Peccaries. 383 



was small and simple. The two succeeding premolars are much 

 larger, but in this specimen are too worn to admit careful 

 description. The molars are low crowned, the third being pro- 

 vided with a large heel. 



Measurements. 



Length of upper dentition 1 'ZO"'" 



Width of incisor 2 8 



Width of incisor 3 -. 5^ 



Length of upper premolar series 35 



Length of premolar 2 .. 11 



Length of premolar 3 _ 11 



Length of premolar 4 13 



Length of molar series 58 



Length of molar 1 19 



Length of molar 2 19 



Length of molar 3 , 20 



Length of lower premolar series. 41 



Length of lower molar series 64 



The following table shows the relative development of the 

 dentition of the various genera of this Tayassuinae family or 

 series: 



Age 



Pei-choerus 



Bothrolabis 



Mid. OligoceiH 

 White River 



[Up. Oligocene 

 John Day 



T-, 41, iLow. Miocene 



Desmathyiis t -d v j 



■' Low. Eosebud 



Pediohyus 

 Tayassii 



Low. Miocene 

 Up. Harrison 



Up. Miocene 

 — Recent 



^^^««-- i%S^e 



Prosthennops 

 Mylohyus 



Up. Miocene 

 Pleistocene 



Dentition 



Incisors 



Equal 



Equal 



In. 1 enlarged 

 In. 3 reduced 



In. 1 enlarged! 

 In. 3 reduced 



In. 1 enlarged 

 In. 3 lost 



Premolars 



All simple 

 All simple 



In. 1 enlarged 



Reduced 



Vestigal or 

 wanting 



P. 4 slightly 

 molariform 



P. 4 molariform 

 P. 3 less " 

 P. 2 " " 



Simple 



P. 3 and 4 



molariform 

 P. 2-4 



molariform 



No notch for lower 

 canine. 



Skull rather brachi- 

 cephaiic. 



Notch for lower ca- 

 nine. 



Skull mesocephalic. 



Notch for lower ca- 

 nine. 



Skull mesocephalic. 



Notch for lower ca- 

 nine. 



Skull mesocephalic. 



Shallow notch for 

 lower canine. 



Skull mesocephalic. 



2 or less transverse 

 crests on upper 

 premolars and 

 molars. 



Skull mesocephalic. 



Skull dolicocepha- 

 lic. 



Skull dolicoeepha- 

 lic. 



