OF MASTODONS, WITH REMARKS, ETC. 
13 
inner; in the upper jaw it is the reverse. As the teeth are used, their 
points become worn down, and the enamel presents a lozenge form, with 
hone in the centre. The roots of the teeth are formed after the crown. 
With the remains of the animal described by Dr Godman, there were 
found a number of points, evidently parts of very young teeth, of 
which the bodies by which they were to have been connected together 
had not yet been formed. These points are now in the Museum of 
Mr Rubens Peale, New York. 
The number of the roots may be said to correspond to the number 
of the denticules. In the teeth with two denticules, the two roots are 
distinct; in those with more than two denticules, the anterior and some¬ 
times the second root are distinct, the others are united but marked 
by distinct grooves. The roots are flattened anteriorly and posteriorly ; 
externally they are slightly and internally deeply grooved. 
The upper teeth may be distinguished from those of the lower jaw 
by their roots being more divergent laterally, and by their crowns 
being broader. 
The teeth differ from one another principally in their size and in 
the number of their denticules. 
In the species of Mastodon which inhabited this country there are 
three kinds of teeth.. 
The first nearly square and having two denticules; 
The second rectangular with three denticules; 
The third longer, generally contracted posteriorly, and having four 
or five denticules and a heel, of various forms. 
The first mentioned teeth are always anterior, next follow those 
with three denticules, and lastly those with four and five denticules; 
but we have never seen those with five distinct denticules in the upper 
jaw, they appear to belong exclusively to the lower. 
In the young jaw described by Dr Godman, we find, 1st, a small 
square tooth, with two denticules; 2d, one rectangular with two den¬ 
ticules; 3d, a tooth with three denticules; 4th, one rather larger, also 
with three denticules. In the upper jaw there are corresponding teeth. 
Each of the two adult lower jaws having tusks (Plates XXVIII. and 
XXIX.) contains a tooth with eight points; and it is manifest that there 
was a corresponding tooth in the upper jaw. The whole number of 
teeth possessed by the animal described by Dr Godman ( Tetracaulo - 
don) is then at least twenty; and we think that it is at least probable 
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