KEMARKS ON THE DENTAL SYSTEM OF THE MASTODON. ^f 



cessive teeth were a gradual and successive enlargement upon this and each 

 other's volume. In the Museum of Mr. Koch at St. Louis, there is a young 

 head, the long diameter of v^hich is eighteen or twenty inches, and where the 

 fact of four co-existent teeth on each side of each jaw, is exhibited. This spe- 

 cimen, with a dozen lower jaws of different ages and sizes, enables us to trace 

 with some accuracy the stages of dentition until it reaches the large solitary 

 grinder of ten inches in length, and on each side. Judging from these phases 

 of dentition, I should infer that the entire amount of teeth was at least twenty- 

 four. 



M. Cuvier had satisfied himself, that the number was at least twelve, and 

 he had almost reached the conclusion, from a comparison of publications, that 

 there were sixteen. To our learned colleague, Dr. Isaac Hays, we owe a fur- 

 ther conclusion on this subject, to wit, that the number was twenty-four.* I am, 

 indeed, not satisfied, on viewing the difference of size between the smallest and 

 the largest tooth of the Mastodon, that the number did not approximate still 

 more that of the Elephant, and amount to at least twenty-eight, and, pos- 

 sibly, thirty-two. 



Among the remarkable observations on the Mastodon, is that of Dr. Godman,t 

 that there were examples of this animal having a short tusk on each side of 

 the chin, and which he named Tetracaulodon. The existence of these tusks in 

 unquestionably adult specimens, as demonstrated by Dr. I. Hays,J quashed 

 the objection that they belonged to the sucking state, and were lost as the ani- 

 mal advanced to maturity. The naturalist was left therefore with the conclu- 

 sion that either a new species of the animal had been discovered, or that it was 

 merely a sexual peculiarity belonging most probably to the male. The perfect 

 similitude of the other teeth with those of the known Mastodon, embarrasses 

 this question deeply, and it may be safely doubted whether we have the ma- 

 terials to solve it. 



In examining the specimens of the lower jaw, in Mr. Koch's Museum in St. 

 Louis, I was struck with some, bearing on this question, and of which there are 



* Description of the Inferior Maxillary Bones of Mastodons. Transactions of the American 

 Philosophical Society, Vol. IV. New Series. 



t Transactions of the American Philosophical Society, Vol. III. New Series, p. 478, 

 \ Loc. cit. p. 82. 

 VIII, — P 



