OP MASTODONS, WITH RE31ARKS, ETC. 
19 
five denticules, the tooth situated towards the inner side of the thick 
ramus. There is also in the same collection, a fragment of the ante¬ 
rior portion of a lower jaw, with the chin rostrated somewhat, like 
that of the Tetracaulodon , but more expanded, and without alveoli. 
It conveyed the idea to some of the naturalists who had examined it, 
of its being the adolescent state of the animal described by Dr God- 
man, the tusks having fallen out, and their alveoli being just obliter¬ 
ated. We cannot, however, consider such a view as the correct one; 
the fact shown by our specimens, that the tusks exist in all ages of 
the animal, is a sufficient disproval of it. 
I must not close this communication without expressing the obli¬ 
gations I am under to various gentlemen, for the liberality with 
which they have facilitated my investigations, and even placed at my 
disposal such specimens as I wished to collect together for the pur¬ 
pose of minute comparison. 
To the liberality of the trustees of the Baltimore Museum, I am indebt¬ 
ed for the use of the splendid jaw of the M. giganteum , belonging to that 
collection. J. P. Wetherill, Esq., with his characteristic liberality, has 
also placed at my disposal his valuable collection, deposited in the cabinet 
of the Academy of Natural Sciences, and the most interesting specimens 
belonging to which are submitted to the inspection of the members. 
Mr Rubens Peale, the proprietor of the remains of the animal described 
by Dr Godman, has also placed at my disposition those remains, and 
the inferior maxillary is now in the cabinet of the Society. To the 
trustees of the University of Pennsylvania and Dr Horner, I am in¬ 
debted for the opportunity of figuring and describing a very fine frag¬ 
ment of a lower jaw belonging to the Wistar Museum.* The pro¬ 
prietors of the magnificent collection of bones, recently disinterred at 
Big-bone Lick, by captain Finnel, and now exhibiting at New York, 
liberally afforded me the greatest facilities in examining that collection, 
and even allowed me the loan of a highly interesting tooth belonging 
to it.f 
* The trustees of the University of Pennsylvania subsequently allowed this jaw to be 
deposited, for several months, in the cabinet of the Philosophical Society. 
t In this collection there are portions of fourteen inferior maxillary bones of the Mastodon, 
about one hundred teeth, some enormous tusks, and the most perfect cranium that has ever 
yet been discovered. 
