30 Cincinnati Society of Natural History. 
found in separate localities in Darke County, O., with the descrip- 
tion of the first known tooth given by Foster, and with the casts of 
the Clyde specimen, it has five times the bulk of any one of them. 
But that does not signify so much as the striking difference in 
form, as will be seen from accompanying plates and description. 
C. ohioensis, so far as I have had opportunity to observe, has little 
or no enamel either on the lingual or proximal surfaces of the upper 
incisors. This Georgia tooth has a well-defined layer of enamel 
entirely around it. 
I propose for this species the name, Castoroides georgien- 
sis; until the discovery of other parts may perhaps throw clearer 
light on its generic relationships. 
DESCRIPAION JOR: PEAS V2 AUN age 
One-half Natural Size. 
CASTOROIDES GEORGIENSIS. 
LEFT UPPER INCISOR. 
IEA WV 
Fig. 1. Showing distal side with its ribs, grooves and cross cor- 
rugations. 
1a. Enamel scaled off. 
1 6. Fore-shortened view of crown. 
1¢, 1c’. Showing how much was free as it rested in socket. 
Fig. 2. The crown, showing line of median fold and scratches by 
enamel of antagonist incisor. 
Fig. 3. Showing section three inches from extremity. 
Nie WD 
Fig. 1. Showing mesial sinus s and plain of clavage. — 
tC. r a breaks, 
LOO) pulpy eawilbye 
Fig. 2. Slab split off from base of Fig. 1. 

