8 
DESCRIPTIONS OF INFERIOR MAXILLARY BONES 
The inferior maxillary bone described by Dr Godman* is very 
accurately represented in Plate XXVI., fig. 1 and 2. The chin, the right 
ramus and a portion of the coronoid process, and about three-fourths 
of the left ramus are perfect. The mental ridge, each side of the labial 
groove, is sharp and smooth, without that remarkable foliated expansion 
so conspicuous in the M. gigantewn (Plate XXIII. s). In the left ramus 
there is still the first deciduous tooth (Plate XXVI. fig. 2, a)on the right 
side the corresponding tooth has fallen out, and its socket is partly obliter¬ 
ated. This tooth (fig. 2) is one inch and five-tenths long, and one inch 
and one-twentieth broad; its surface is considerably worn, most so an¬ 
teriorly. It had four points; anteriorly there is a fold of enamel which, 
commencing at the external edge of the base of the crown and passing 
upwards and inwards, terminates in a point; posteriorly there is a some¬ 
what similar and rather broader fold of enamel. Anteriorly the crown 
is rounded; posteriorly it is flattened from contact with its successor; 
its grinding surface is considerably w'orn. It has tw T o roots, one ante¬ 
rior, the other posterior. 
We have seen in the cabinet of William Cooper, Esq. of New York, 
a fragment of a lower jaw containing one of these teeth exceedingly 
perfect; its points are scarcely perceptibly worn. Another specimen 
is in the cabinet of the Academy of Natural Sciences.f 
The second tooth (Plate XXVI. c) is one inch and eight-tenths long, 
and one inch and eleven-twentieths broad. This tooth, like the preced¬ 
ing, had two denticules, with two points each. On the anterior of the 
crown there is a flat fold of enamel similar to that on the first tooth. 
This tooth has also a heel which rises highest towards its inner aspect, 
forming a small fifth point. The grinding surface of this tooth is 
considerably worn. This tooth like the preceding one has two roots; 
one anterior, the other posterior. 
In the Finnel collection there is one of these teeth; it is one inch 
and seven-tenths long, and one inch and five-tenths wide. 
* Vol. III. p. 478. 
t This tooth is described in the “ Fauna Americana,” as appertaining to a new species of 
Tapir to which the name T. Mastodontoideus is given. Mr William Cooper was we believe 
the first to detect this error; we have carefully examined the tooth, and there can be no doubt 
of its being the first milk tooth of the animal we are describing. 
