OF MASTODONS, WITH REMARKS, ETC. 
23 
Plate XXV. Two views of a fragment of a lower jaw, right side, of a Mastodon, in the 
cabinet of the American Philosophical Society. 
f. Posterior molar, with four points and a broad heel. 
e. Penultimate molar, with three points. 
Plate XXVI. Fig. 1 and 2. Two views of the fragment of a lower jaw of a young Te~ 
iracaulodon, in Peale’s Museum, New York, described by Dr Godman, in Vol. III. N. S. of 
the Transactions of the American Philosophical Society. 
a. Anterior milk molar, with two denticules. 
/). Second milk molar, with two denticules, and a small process, 
c. Third milk molar, with three denticules. 
The tusk belonging to this jaw is accurately represented in Plate XVIII. tig. 2, in Vol. III. 
N. S. of these Transactions. 
Fig. 3. Tusk of an adult Tetracaulodon, in the cabinet of the Academy of Natural Sciences 
of Philadelphia, deposited by J. P. Wetherill, Esq. 
Plate XXVII. Three views of a portion of a lower jaw, right side, of an adolescent Tetra¬ 
caulodon, in the Museum of the University of Virginia, and to which allusion is made by Dr 
Godman, in his memoir in the preceding volume of these Transactions. 
f. Posterior molar, with four denticules and a heel. 
e. Penultimate molar, with three points. 
Plate XXVIIL Two views of a portion of the lower jaw, right side, of an adult Tetracau- 
iodon in the cabinet of the American Philosophical Society. 
f. Posterior molar with four points. 
p. q. Mental foramina. 
r. Radiated muscular impressions. 
t. t. Tubercles, where the muscle was inserted. 
v. Inner point of second denticule. 
The socket for the tusk could not be exhibited, but its situation is shown by the dotted line 
representing a tusk. 
Plate XXIX. Two views of a fragment of a lower jaw, right side, of an adult Tetracaulo¬ 
don, in the cabinet of the American Philosophical Society. 
x. Excavation between the coronoid process and posterior molar. 
f. Posterior molar, with four points and a heel. 
z. Socket for tusk. 
Philadelphia , December 2, 1831. 
