202 MAMMALIAN DENTITION 



The enamel on the distal aspect of the upper canine is ar- 

 ranged in three ridges ; the distal aspect of the lower canine is 

 devoid of enamel. The rows of cheek teeth are almost parallel 

 and the palate terminates behind the last molar. The pre- 

 molars in both jaws increase in size and complexity from the 

 simple first to the molariform last. A molariform crown even 

 for the last premolar is by no means common among the Arti- 

 odactyla. The most anterior lower premolar (P2 of the primi- 



Fig. 72. — Dentition of Red River Hog (Potamochoerus, porcus, 9.731-1). This ani- 

 mal possesses a dentition more primitive in certain respects than that of the domestic 

 Pig. The rounded cusps and accessory cuspules on the molars and the elongation of 

 the last molar indicate the root diet. Compare the dentition of the Baboon (Fig. 43). 



tive placental dentition) is lost relatively early in life. The 

 molars are brachyodont, bunodont and quadricuspid in form, 

 the paraconid of the lower teeth being absent. But the well- 

 rounded appearance of the cusps like the multitude of addi- 

 tional cuspules is secondary in character and related to the 

 type of food eaten. So also is the marked elongation of the 

 last molar in each jaw, the extension of the talon and the tal- 



