Manitellian Museum at Lewes. 15 
effected is clearly that of mastication.* The recent iguanas 
alone have teeth resembling those of the Iguanodon, particu- 
larly in the angular form of the crown, and the serrated edges, 
as may be seen at d, which represents one of these teeth 
greatly magnified. The metacarpal bones, or those of the 
feet and toes of the Tguanodon, are of enormous size, one of 
the tarsal bones measuring 13 in. in circumference; the un- 
guial bone is also in the museum, only one ciaw has hitherto 
been discovered. It appears, also, that this remarkable animal 
had a horn (e), which nearly resembles in size and form that 
of the rhinoceros; it has a bony structure, but it was not 
united to the skull like the horns of Mammalia. It is to Mr. 
Pentland, an eminent naturalist who has studied several years 
under Cuvier, that we are indebted for information respecting 
the nature of this extraordinary fossil; when a cast of it was 
first shown to him, he sug vested that it belonged to a saurian 
animal. <A species of living i iguana, a native of St. Domingo, 
has between the eyes an osseous conical horn or process, 
covered by a single scale; hence this animal is called the 
Horned Iguana, or Jeudna cornita. ‘This fact, Mr. Mantell 
observes, establishes another remarkable analogy between the 
Iguanodon and the animal from which its name is derived. 
¢ aWe have seen,” says Mr. Mantell, ‘ that the teeth are at 
least twenty times larger than those of the iguana of 3 or 
4 ft. in length, that the thigh bone is of equally enormous 
proportions, and were we to calculate the probable magnitude 
of the original, from the data which the metatarsal bone 
affords, vie. might well exclaim, that the realities of geology 
exceed the fictions of romance.” 
There is the highest probability, from the resemblance of 
the teeth and large bones found in Tilgate Forest to those of 
the iguana, that both the teeth and Hoites belonged to one 
species of unknown animal; but, as no portion of the jaw has 
hitherto been found, we have not at present obtained an abso- 
lute cer tainty respecting this fact. Cuvier, in the last edition 
of his Régne Animal recently published, says that the cha- 
racter of the Geosatirus + of Sammering, the Megalosatrus of 
Buckland, and the Iguanodon of Mantell, are not yet so com- 
pletely ascertained as to enable us to class them with cer tainty. 
Should it be eventually proved that the large bones and the 
teeth, found in Tilg ate Forest, be slonged to different animals, 
* Mr. Mantell conjectures that the food of the Iguanodon consisted 
chiefly of plants furnished with rough thick stems, as indicated by these 
remains ; hence a peculiar structure of the tooth was required. 
ate Geo saurus, earth lizard. Megalo saurus, great lizard. 
