305 
as well as in the structure, figure, and insertion of the teeth ; although, 
in this latter respect, there exists a peculiarity in the fossil animal. 
In the monitor, as in the iguana, the teeth simply adhere to the in- 
ternal surface of the two jaws, without the maxillary bone rising to 
form sockets round them ; but in the fossil animal, the feet, or bony 
nuclei, which sustain the teeth, are adherent in the cavities, or real 
sockets, formed in the thickness of the edge of the jaw. 
In the fossil upper jaw are eleven teeth ; but, as the intermaxillary 
bone appears to have been removed, and as it might have contained 
three teeth, as in the monitors, it most probably contained the same 
number in the upper as in the lower jaw. The water-monitor of 
Egypt has fourteen at the top, but only twelve at the bottom. 
In the fossil animal all the teeth are pyramidal, and a little bowed ; 
their outer surface is flat, and is separated, by two sharp ridges, from 
the inner surface, which is round, or rather semi-conical. Some of 
the monitors have conical teeth, and others have them rather flat and 
edged ; all the iguanas, and even the lizards and ameiva, among which 
mav be reckoned the pretended tupinambis, or monitor of America,* 
have teeth with dentated edges. 
Thus far, then, the fossil animal of Maestricht appears to approach 
nearer to the monitors than to any others of the lizard tribe ; but a fur- 
ther examination, at once, shows a remarkable variance of character ; 
the palate-bones being armed with teeth, which at once approximates 
it to the iguanas. 
M. Cuvier has, by his rich resources in comparative anatomy, been 
enabled to determine that the crocodiles, the monitors, the common 
lizards, the dragon of Lacepede, the dracena of Linnaeus, the ameiva , 
draco , stellio , agama, hasiliscus , gecko, camceleo, scincus, and 
chalcides, are without teeth on the palate -bones. The iguana and 
* This American monitor differs from those of the old continent, and approximates nearer 
to the common lizards, by its teeth, with dentated edges, and by the square scales of its belly, 
tail, &c. 
VOL. III. 
R R 
