OF MASTODONS, WITH REMARKS, ETC. 
7 
The posterior molar (Plate XXIV. f) has but eight points, and the heel 
is broad, whilst in our specimens of the M. giganteum the posterior 
molar has ten points and a mammillaform heel. The direction of the 
teeth is also very divergent anteriorly. Are these differences suffici¬ 
ent to indicate its belonging to a different species from the M. gigan¬ 
teum ? 
There is, in the cabinet of the Society, a portion of another jaw, 
consisting of the left ramus, containing two teeth, and the chin ; which 
is entirely similar to the above in its characters, but somewhat dis¬ 
torted, no doubt from injury when the animal was young. There is 
another specimen resembling the above in its general characters, among 
the lower jaw bones of Mastodons belonging to J. P. Wetherill, Esq. 
and which are deposited in the valuable cabinet of the Academy of Natu¬ 
ral Sciences of this city. This fragment, however, has had the teeth 
broken out.* 
The cabinet of our Society contains a portion of an inferior max¬ 
illary bone, (Plate XXV.) which differs in its form from any of those 
hitherto described. This fragment consists of the chin, the right ramus, 
with the posterior molares, and a portion of the left ramus. The 
anterior molar (Plate XXV. e) has three denticules with two points 
each; the posterior (fig. /) has four denticules, with two points 
each; and a ridge posteriorly. The ramus of this jaw is straighter, 
and more cylindrical; the height from the base to the edge of the al¬ 
veole is less; the groove for the tongue broader and shallower; and 
the direction of the teeth less diverging than in the maxilla figured in 
Plate XXIV. The crowns of the teeth are also less elevated in the 
former than in the latter. 
In the collection deposited by Mr Wetherill in the Cabinet of the 
Academy of Natural Sciences, there is a fragment of a lower jaw, 
which exhibits the same characters as the one just described. This 
fragment consists of the chin, about eight inches of the left and twelve 
inches of the right ramus. The alveolar processes are much broken, 
and the teeth are lost. 
* This jaw was exhibited to the Society. 
