147 



referred to at previous meetings of the Society, and made 

 the following communication : — 



The Society may recollect that, two or three meetings since, 

 I made a statement on a case of supernumerary tooth in the 

 Mastodon giganteus ; and, at the last meeting but one, I laid be- 

 fore the Society a communication on the subject from my friend, 

 Mr. Lapham, of Milwaukee, which has been already published. 

 This very curious anomaly is now in my possession, and I have 

 the pleasure of laying it before the Society for their inspection 

 and opinion. 



When this jaw was received by me, I readily distinguished the 

 characters of the fifth tooth, and also of the sixth. Behind the 

 latter, were seen the first two ridges, and part of a third protrud- 

 ing through the bone, and behind these were indications of other 

 portions of the tooth, which could not be examined. In order to 

 fully display the concealed part, I determined to remove a suffi- 

 cient portion of the bone to expose the body and the fangs of 

 this tooth. This was done, not without reluctance, as it might 

 have disturbed and loosened the additional tooth, and obscured 

 its relations. It was, however, happily accomplished without 

 altering the connection to surrounding parts, and after the oper- 

 ation the tooth remained secure in its situation, and capable of 

 being only slightly moved. A horizontal incision, six inches 

 long, was made opposite the roots of the tooth, on the inner side 

 of the jaw ; this was joined at its anterior extremity by another 

 incision, about four inches long, also by a similar one at the 

 posterior. Then, by a chisel introduced in a vertical direction, 

 between the maxillary ridge and the tooth, the alveolar process 

 was cut oflT, though not without much labor and difficulty. When 

 the bone was removed, the very extensive alveolar cavities, and 

 the large, long, curved fangs, with the great dimensions of this 

 concealed tooth, were exposed. 



The number of teeth belonging to the Mastodon giganteus 

 was for some time undetermined. In my publication on the 

 M. giganteus^ I have shown that, by the labors of Cuvier, 

 Hays, and others, this number has been established to be twenty- 

 four, i. e. six on each side of each jaw, excluding the tusks, 



