2 
DESCRIPTIONS OF INFERIOR MAXILLARY BONES 
describing, as a new animal, the young of a known species. The 
account of the Tetrcicaulodon was, however, written by the author, 
literally on his death bed.* There is no need of the Society’s being 
reminded of the generous and lofty ambition, by which Dr Godman 
was always actuated, or that he was compelled through life, to struggle 
against difficulties, which no ordinary man could have overcome; and 
they will at once understand his expression to his friends, on announcing 
that he was preparing an account of a new fossil animal,—I have 
all my life,” said he, “ been compelled to labour for bread, I shall now 
do something for my fame.” 
These remarks will account for such imperfections as may have 
occurred in Dr Godman’s memoir, as also explain my anxiety to secure 
to him the credit which appears to me to be his due. 
It is not my purpose to inquire into the value of the tusk, in the 
lower jaw, as constituting a generic distinction between the Mastodon 
and Tdracaulodon.^; Generic divisions in science are, for the most 
part, as yet too arbitrary—the characters upon which they are founded 
too ill determined—and our materials at present too scanty, to induce 
us to venture any remarks upon this subject, even had we not deter¬ 
mined to restrict ourselves to a detail of facts. 
A more important subject of inquiry, is whether the Tdracaulodon 
is merely the young of the gigantic Mastodon , and the tusks in its 
lower jaw only milk teeth, which are lost when the animal becomes 
adult and are never replaced. Fortunately the cabinet of the Society 
furnishes us with materials for at once settling this question. It con¬ 
tains portions of three lower jaws, which 1 have the honour of exhibit¬ 
ing, and which will be particularly described hereafter. The first is 
that of a young Mastodon, M. giganteum (Plate XX.), entirely destitute 
of tusks or alveoli for tusks; the two others appertain to aged adult 
animals (Plates XXVIII. and XXIX.), and exhibit distinct sockets for 
tusks. A more complete refutation then of the assertion that the Tetra- 
* Dr Godman died before the number containing his memoir was published. 
t Mr Titian R. Peale, who was the first naturalist by whom the Tdracaulodon was seen, 
suggested to Dr Godman that the tusks in the lower jaw might be merely a sexual character. 
It is impossible, in the existing state of our knowledge, and with our present materials, either 
to confirm or positively refute this suggestion. 
