290 



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, ap- 

 pears 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, b.\ 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 the preceding bone. 



h, i A fragment of the left side of the upper jaw, displaced and 



fallen on the lower jaw. 



k y I, m, 7 The two palate-bones, displaced and thrown one over the 

 k', l',m',o', ) 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. 



In the lower jaws are fourteen similar teeth on each side, but the mo- 



