‘* 
430 Scientific Intelligence. 
lands by powerful streams oc currents, nearly a quarter of a century 
elapsed before any portion of mm retaining teeth was discovered. 
The most important relic of this kind is described in oo po ea it 
consists of the anterior part of the right side of ‘the lower jaw, ¢ 
prising about two-thirds of the dentary bone, and was Jincmveet by 
Captain Lambart Briekenden, who, in the true spirit of a man of sci- 
ence, liberally placed it at the disposal of Dr. Mantell, as the original 
discoverer of the fluviatile origin of the wealden formation of the south- 
east of England. 
is bone is eighteen inches long; and if the proportions of the 
maxillary elements. in the Iguanodon were the same as in the recent 
Iguana, the entire jaw must have been four feet in length. It contains 
several of the new or successional ‘teeth in-their natural: ‘position, and 
there are Pontos in the alveolar plate for nineteen or twenty mature mo- 
lars; but all these teeth are Wanting, having evidently been dislodged 
before the bone was imbedded in acstotie: The mature teeth, which 
in their abraded state resemble those of the’ used molars of SS ae 
mammalia, appear to have been arranged i in a closely set se 
teeth in the lower jaw were placed with theirpflat stitch ‘striated 
face towards the inside of the mouth, while those in the upper were 
disposed i in the opposite position—namely, with the enamelled ridged’ 
face of the crown externally ; and the teeth of the upper and lower 
series were su alga or intermediate‘ in their relation to each other, 
as in the rumina 
The anterior i of the lower jaw, which forms the symphysis, pre- 
sents a most remarkable deviation from all known reptilian types; the 
alveolar parapet, instead of ‘being moe round the front of the 
uth, and bearing teeth, as is the case in all saurians, is edentulous; 
and at the distance of fourvor five iabhes ye the front of the chin, 
suddenly contracts ina vertical direction, becomes procumbent, and 
expands horizo ontally to meet the correspo nding portion of the o pposite 
ramus 0 they jaw: the two symphysial portions when united, forming 
a déep scoop, bear considerable analogy. to the mics es part 
the Edentata, especially in the extinct colossal Mylo 
external surface‘of the jaw there is a row of very large 
amin and the a eer is also perforated by 
_blood-vessels and nerves 
ASIde | e furhor, is now in 
, Cor Hin th Satoephonl didwet from the examina- 
er ja and teeth. The author, with the able assistance 
ed a comparison between the fossil teeth in his 
own, and in the British Mu with those of FY lizards, and the 
result of their labors is fully detailed} in this memo 
The light shed on the stracture and functions of the dental organs 
Ig: -tanodon by these recent discoveries, confirms in every esse 
“ater eatae the inferences deduced, oe i Mantell from eh duinchil 
teeth alone, and detailed in his memoir nd it veals the 
remarkable fact, that this saurian epitita ual j in in balk domo 
gigantic ic Megat herium and Mylodon, and , like them, 
= 
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