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 js 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, 
assing 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 <Sencigs in the jaw and the head to which it was at- 
tached. Fig. 1 
aie ais animal was doubtless a Gnawer, perhaps of the 
Beaver family ; or from the grooved outer surfaces of the incisors, 
Vol. XXXI.—No. 1. , 11 
