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from the jaw, occasioning it to fall off, by a species of necrosis like that 
by which the horns of stags are separated ; the Secondary tooth, and 
the osseous body which supports it, filling the place of the tooth which 
has been expelled. The cellular and osseous body supporting the teeth , 
and which have been erroneously assumed by M. Faujas, as well as 
by others, as the root of the tooth, appears to be the pulp of the tooth; 
which instead of remaining pulpy, as in quadrupeds, ossifies, and 
performs the office of a root, becoming one body with the bony socket. 
This mode of organization and of dentition sufficiently distinguishes 
this animal, therefore, from the crocodile, and indeed displays further 
proofs that it cannot be considered as a cetaceous animal : M. Cuvier 
is, therefore, induced, to place it between the osseous fishes and the 
iguana and tupinambis. 
To enable you to form a better judgment respecting the opinions of 
M. Cuvier, to which I shall now call your attention, I have given, 
Plate XIX. Fig. 1, a copy of the engraving of the large head of this 
animal, from Plate XIX. Vol. xn. of Annales du Museum, &c. 
a, h The left side of the lower jaw, nearly whole, and seen on 
its outer side. 
c } d The right side of the lower jaw, seen on its inner side, 
the posterior part of which, a little concealed by the 
palate-bones, is continued to e. 
f ; g The right side of the upper jaw, seen on its inner side, 
and with the palate. This jaw has nearly kept its 
natural situation, with respect to its preceding bone. 
h, i A fragment of the left side of the upper jaw, displaced 
and fallen on the lower jaw. 
k, l, m, } The two palate-bones, displaced and thrown one over 
k', l’, m, o’, j the other, and also over the right side of the lower jaw. 
In the original specimen, a portion of bone is placed from m to p, 
and another at q, which are omitted ; as, being mutilated, they cannot 
be made out, and conceal the more instructive pieces. 
