26 Cincinnati Soctety of Natural History. 
DESCRIPTION OF A. NEW SPECIES "Of Giger 
BEAVER-LIKE RODENT. 
By Pror. JosepH Moore, oF EARLHAM COLLEGE, RICHMOND, 
INDIANA. 
THE tooth which is the subject of this sketch was found in 
Northern Georgia in the late war time by Dr. C. S. Arthur, of 
Portland, Jay County, Ind. 
The Doctor, who has a habit of looking for specimens, was 
searching some old forsaken gold diggings, in the hope of adding 
some ‘‘ dust” to his collection, when he discovered near the bot- 
tom of a gravelly pit one end of the specimen now before us. It 
was six to eight feet below the surface, and, as the Doctor informs 
us, was taken out entire. 
The cracks and breaks are probably the result of drying or of 
exposure in carrying. 
I take this specimen to be the left upper incisor of some Rodent 
—very probably of the Genus Castoroides. As some experienced 
observers have questioned as to the place of the tooth, I offer the 
following reasons for thinking it can not be a lower incisor : viz., 
since the branches of the lower jaw meet at an angle and the 
incisors are bedded posteriorly in the outer portion of the jaw, they 
must rapidly approach each other as they extend forward from their 
bases, so that as they project from their sockets they would cross 
each other if they did not twist outward. This direction of lower 
incisors towards each other in their growth causes them to crowd 
together and sustain each other. As a consequence they are worn 
on their adjacent surfaces. This tooth has xo fwist and 20 wear on 
its proximal surface. 
In the second place, the curvature of the tooth is quite too rapid 
for a lower incisor. 
Its weight is . : : : : . 241% OZ. av. 
Its length along border ai Bre ures convexity is . 18% inches. 
Length of inner curve from base to hinder edge of bev- 
eled crown, : : : : Se ebie “e 
Distance across from base to apex, outer to outer point Tig 
Greater diameter, fore and aft, at base, . ; Pee 

