504 F, Raw—A Mammoth Molar from North Woodchester. 
while in front the grinding surface cuts across the base of the crown, 
exhibiting the bottom of an enamel infold. Twelve plates are 
evidenced together with a talon behind, but it is impossible to say 
how many have been ground away entirely in front. 
The curved shape of the base of the crown and its relative shallow- 
ness indicate that this is a lower molar, and since when looked at 
from above the plates run obliquely forward to the left, it is seen to 
belong to the right side of the mandible. 
Posteriorly the crown narrows like the prow of a ship to a relatively 
fine edge, and thus gives no suggestion of pressure being exerted 
through a tooth following it in the jaw. This would indicate that 
it is the last tooth or third true molar. Its characters thus indicate 
an ultumate right lower molar. 
For specific determination of such teeth reliance is placed on the 
form and spacing of the “plates” and the thickness and form of 
the enamel layers as seen in section on the grinding surface. In the 
Woodchester specimen the plates are closely spaced and the dentine 
and cement are in parallel bands and almost exactly equal to one 
another, but the posterior plates are drawn forward and constricted 
near their middle. The closeness of the plates is indicated by the 
length of tooth for a definite number of plates. There are ten 
complete folds in 5°75 to 6 inches or eight full size in 4:6 inches. The 
enamel is about ‘06 in. thick, is crimped, and especially throughout 
the posterior half of the tooth forms compressed outfolds on the 
plates. These characters taken all together indicate Hlephas 
prumigenius or the Mammoth, though each of these characters could 
without doubt be matched among teeth ascribed to EHlephas antiquus. 
According to Dr. Adams! the number of plates, not counting the 
talon or heel at each end in the last molars of the mammoth ranges 
from 18 or 19 to 27, the width from 2 to 44 inches, the closeness of 
the plates from eight plates in 5in. to the same number in 3:1 in. 
In our tooth the measures given above of width (23 in.), and closeness 
of plates (eight in 4°6 in.), fall well within this range. But asalready 
noted detrition here is very far advanced, the remaining portion of 
the crown varying from | in. deep behind, through 2 in. at its deepest, 
to Oin. in front and so the number of plates is quite unknown. 
And as the commonest number of plates in these teeth is probably 
22 or 23, the plates at the anterior end which are worn right away to 
the base are the middle ones of the entire tooth. Thus the superior 
surface probably measured originally 14 in. or 15 in. by 23in., while 
we may take the original depth of the crown as probably 4 in. or 
45 in. The animal was thus in advanced old age, and had worn 
away all but one-sixth or one-eighth of the volume of the crown of 
its last teeth. 
Moreover, the occurrence of a continuous keel below the crown in 
place of a number of fangs seems to be characteristic of the last part 
1 A. Leith ae ns, “ British Fossil Elephants”: Palwontographical Society, 
1877-81, p. 12 
