THE TEETH OF VEETEB-EATES 73 



the entoconid. The position of the talonid is such 

 that the hypoconid falls in the center of the trigon 

 of the npper molar (Fig. 20). There is then de- 

 veloped on the disto-lingnal surface of the trigon 

 (upper molar) a talon which carries a cusp called 

 the liypocone, thus making a quadritubercular 

 molar as seen in the upper molars of man. This 

 fourth cusp falls between the lower cusps as 



Fig. 21. — Diagram showing the position of the talon of the upper molar. 



1. Protoeonid (Mesio-buccal cusp). a. Protoeone (Mesio-lingual cusp). 



2. Paraconid (Mesio-lingual cusp). b. Paracone (Mesio-buccal cusp). 



3. Metaconid (Disto-lingual cusp). c. Metacone (Disto-buccal cusp). 



4. Hypoconid (Disto-buccal cusp). d. Hypocone (Disto-lingual cusp). 



shown in Fig. 21. The cusps of the lower molar 

 continue to develop and change. The paraconid 

 becomes reduced in size and is missing in the 

 lower permanent molars of man, but exists in the 

 deciduous lower first molar as a small cusp. The 

 paraconid can also be seen in the lower teeth of 

 the opossum. The position of the paraconid and 

 the cusps of the talonid, as seen in the lower first 

 deciduous molar of man, is shown in Fig. 22 with 



