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In the lower jaw are fourteen similar teeth on each side* but the 
monitors have only eleven or twelve ; and the crocodiles have fifteen, 
which are very unequal. In this jaw also are from ten to twelve large 
and pretty regular holes. In the Monitors are six or seven, and 
in the Crocodiles a considerable number of small and irregular 
openings; whilst in the Dolphins there are but two or three, which 
are towards the end. 
At p is an obtuse raised coronoid apophysis, the anterior ridge of 
which is enlarged, as in the monitors. In the crocodiles there is 
nothing similar, in the dolphin it is smaller and much backwarder, 
and in the iguana it is more pointed. The articulating surface, r, is 
concave, and very near the posterior end, as in all the lizards ; but 
it is lower than the dental edge, as in the monitors ; in the crocodiles, 
and in the iguanas, it is higher. In the dolphins it is convex, and 
placed quite at the end. The apophysis b, for the attachment of the 
muscle analogous with the digastric, is short, as in the iguana ; in 
in the crocodile it is longer ; and still more so in the monitor. 
The formation of the lower jaw shows that this animal more nearly 
accorded with the monitors than with any other of the lizard tribe : 
as to the cetacea, there exists no resemblance ; since in these, as in 
all the mammalia, each side of the lower jaw is in one piece. But to 
be convinced of the closer agreement of the lower jaw of the fossil 
animal with that of the monitor than with that of the crocodile, it is 
necessary to attend to the following comparison. 
In the lower jaw of the crocodile are six bones on each side : the 
dental, in which are formed the alveoli of the teeth, the two being 
articulated with each other, in the fore part, and forming the anterior 
angle ; the opercular, which forms almost all the inner surface of the 
jaw, except on the fore part where it is formed by the dental ; the 
coronoidal, with the angular; the former placed over the latter, reach- 
ing to the posterior extremity ; leaving between them a space in the 
fore part, which is occupied forwards by the end of the dental, 
