THE LOWER JAW. 



3T 



The coronoid process of the lower jaw in Dinoceras is large and 

 elevated, somewhat curved backward, and pointed a,bove (Plate VIII, 

 figure 1, cr). The angle of the jaw is rounded in outline, and projects 

 downward somewhat below the main portion of the ramus. The dental 

 foramen is large, and bounded above by a ridge, which extends upward 

 and backward to the condyle. The mental foramen is of moderate size, 

 and situated near the base of the anterior pendent process. 



Figure 38. — Lower j:i\v with U|iper caniiiL- in positiou of Tinortruf: luwiia-ps. Jlui-sh (Xu. l-oij), female ; seen 

 from the left. 



a. angle of jaw ; c, upper canine tnoth in its natural position ; c'. lower canine tooth ; cd. comJyle ; 

 cr. coronoid process; d. diastema; p. process for protection of canine tusk. 

 One-fourth natural size. 



In the genus Tinoceras, the same general characters of the lower jaws 

 are seen. In tlie male, the pendent process is large and elongate, but less 

 massive than in the genus Dinoceras, and its lower outline less regularly 

 rounded (Plate XIX, figui-e 1, cp). This corresponds with the position of 

 the large upper canine tusk, which it protects. 



In the female of Tinoceras, the pendent process is much reduced, its 

 size in all cases corresjionding to the size of the canine tusk above. In 

 the female of Tii/nri'ras Im/i/ireiis (figure 3S, above), the lower jaw is 

 remarkably long and slender, and the pendent ])rocess nearly obsolete. 



