OF TILGATE FOREST. 
271 
resoudre le problcme.” In the second part of the 
fifth volume of the O.s.semens F'ossiles, the learned 
author figures several of these teeth, and minutely 
describes their form and structure.* From the 
resemblance of the perfect specimens to the teeth 
of certiiin s]>ecies of Iguana, I proposed to distin- 
guish the fossil animal by the name ot' Igua?wdo?i; 
and a memoir on the extraordinary dentiiture of 
the original was read before the Royal Society, 
and honoured with a ])lace in its transactions, t 
In the ])erfect teeth, and in those which have 
been but little worn, the crown is somewhat of a 
])rismatic form ; widest and most depressed in 
front ; convex posteriorly, and rather flattened at 
the sides. As soon as the tooth emerges from the 
gum it gradually enlarges, and its edges apj)roach 
each other and terminate in a point, making the 
upper part of the crown angular ; the edges form- 
ing the sides of this angle are deeply serrated or 
dentated ; see fig. 1. p. 270. The outer surface of 
the crown is covered with a thick enamel, but on 
the sides and back a thin coating of this substance 
only appears, as in the incisors of the gnawers. 
Dr. Buckland has pointed out to me, that the dis- 
position of this enamel is not in straight lines, but 
in curves, so as to represent a series of gouges, as 
is beautifully shewn in fig. 1. p. 272. ; by which 
the tooth was rendered more durable, and better 
capable of resisting mechanical injury. The ante- 
* Oss. Foss., vol. V. p. 350. 
f Notice on the Iguanodon, a newly-discovered fossil herbivorous 
reptile, from the sandstone of Tilgate Forest, in Sussex. — Philosophical 
Transactions, 1825, part i. 
