OF TILGATE FOREST. 
273 
several finer lines are observable : a specimen of 
the former is shewn in fig. 1. p. 27O., and of the 
latter variety in the same cut, fig. 2., and in the 
figures in the above representation. The sliank 
or fang of the tooth partakes of the form of the 
crown ; it is slightly curved, rather flat anteriorly, 
and convex })osteriorly, and much depressed at the 
sides ; it gradually diminishes in size towards the 
base. The magnitude of the teeth is shown by 
the drawings, all of which are of the natural size : 
we have a young and almost perfect tooth in our 
possession, which is two inches and a half in lengtli ; 
being twelve times the length of the teeth of the 
recent Iguana : tlie largest specimens figured are 
twenty times larger than the teeth of that animal. 
All the teeth we have noticed possess traces of 
the characters above described ; the vast difference 
of form they exhibit, depending on a cause which 
we shall now proceed to explain. In tlie elegant 
specimen, fig. 2. and 3. p. 272., we perceive the 
first variation from that angular form, which we 
have already stated to have been the original shape 
of the crown ; and if we observe the internal sur- 
face at b^ fig. 2., we see that tlie point of the tooth 
has been partially worn away, leaving an oblique 
triangular surface : if the reader compare this 
apjiearance with the surface of the perfect tooth, 
Jig. 1. p. 270., he will form a correct idea of the 
change that has taken place. In a series of speci- 
mens, this wearing away of the crown of the teeth 
may be observed in every stage, from tlie slight 
appearance jierceptible in fig. 2, 3. p. 272., to 4, 5. 
of the same, and fig. 2. of p. 270., in which the 
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