14 Mantellian Museum at Lewes. 
pared with the relative size of the teeth of the Mammalia. 
To form some notion of the immense magnitude of the 
animal, it may be useful to mention that I measured the 
circumference of the condyle, or joint, of a thigh bone in the 
museum, and found it to be 35 inches ! and the thigh bone of a 
larger animal, at a distance from the condyle, measured 25 in. 
in circumference. Mr. Mantell justly observes, in his mterest- 
ing work on the fossils of Tilgate Forest, “* Were this thigh 
clothed with muscles and integuments of suitable proportions, 
where is the living animal with a limb that could rival this 
extremity of a lizard of the primitive ages of the world?” 
In the teeth which have been litthe worn the summit is 
pointed, as at fg. 1. a, which represents the front view of the 
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perfect tooth of a young animal; but as the animal increases 
in size and age, the point becomes worn down, as repre- 
sented at 6, which is the front view of a full-erown tooth 
of the natural size. The anterior surface of the tooth d is 
divided longitudinally into slightly concave furrows, by obtuse 
ridges, the most prominent of which is generally on one side. 
In the young tooth (a) seldom more than one ridge occurs, 
dividing the surface into two unequal parts. As the animal 
advances in age, the furrows become obliterated by use and 
the front worn down, as represented atc. With’ a further 
eh of age, the tooth is more and more worn down, till it 
1 ¢ ay ‘ Bi ee ay 
poe a mere bony plate. This wearing away of the crown 
of the tooth may be traced in every stage of its progress, 
. Ait Fes . 2 . 
pope ere sorm in Mr, Mantell’s museum. Baron Cuvier 
observes tha ‘ i 
at the process by which these changes have been 
