Cabinet of the Atheneum at Zanesville. 81 



Fig. 17. Fig. 15. 



Figures one fourth size. 



Inferior Incisor, — The lower incisor is much less curved than the 

 upper, and is longer than the whole jaw, being no less than nine 

 inches in length and one inch in diameter. The two inner surfaces 

 are smooth and plano-convex, while the outer surface is deeply- 

 grooved, and the whole is coated with a dark brown glossy enamel. 

 It is strongly inserted into the jaw opposite the last molar tooth, 

 passing under them all. The cutting extremity is trenchant and 

 beautifully fitted for cutting wood or bark. Its left inner surface for 

 two inches near the end is considerably worn, from friction with the 

 upper incisor. The muscular impressions are very profound, giving 

 proof of great strength in the jaw and the head to which it was at- 

 tached. Fig. 17. 



RemarTcs. — This animal was doubtless a Gnawer, perhaps of the 

 Beaver family ; or from the grooved outer surfaces of the incisors, 



Vol. XXXI.— No. 1. 11 



