14 



Elephants. 



Mastodon. 



Pier-cases, 

 Nos.37&38. 



Proboscidea — Mastodon and Elephant. 



three true molars in the adult, thus making a complement of 

 thirty -four teeth during life. 



In living elephants there are two incisors, called " tusks,'' 

 in the upper jaw, but the lower jaw is without incisor teeth. 



In the Dinotherium, an extinct genus related to the 

 elephants, this order' is reversed, there being two tusk-like 

 incisors in the loicer jaxv, and none in the upper (see Fig. 10, 

 p. 11). 



In Mastodon longirostris there were tusk-like incisors de- 

 veloped both in the upper and lower jaws (see Fig. 14, p. 13). 



In Mastodon americanus, two tusk-like incisors, of large 

 size, were present in the upper jaw in the adult, and two small 

 incisors were developed in the mandible in the young, one of 



Fig. 15. — View of the grinding-surface of a lower Molar of the living Indian Elephant. 

 (Elephas indicus, Linn.) 



which was occasionally retained in the adult (probably the male) 

 individual. (iSee specimen No. 17,147, in Pier-case No. 38, a 

 mandible showing the three true molars on either side, and the 

 right incisor present.) 



Fig. 16.— View of the grinding-surface of an upper Molar of the living African Elephant. 

 (Elejiltas (ifricani'S, Blum.) 



All these animals had, like the living elephants, a cylindrical 

 trunk or proboscis (snout) with a prehensile extremity, serving 

 to gather and convey the food to the mouth. The soles of the 

 feet, supporting the weight of so vast a body, are covered with 



