214 APPENDIX. 



PLATE VI. 



The cranium connected with the lower jaw of Plate V. It exhibits the same teeth, with 

 the exception of the anterior tooth existing on the right side of the former plate. 



The anterior part of the palatine fossa, and of the intermaxillary bones, is more perfectly 

 seen here than in the other plates. 



PLATE vn. 



This is intended to show the masticating surface of the sixth or ultimate molar, in place, 

 with its ten points. In front — i.e. at the upper part of the plate — is the penultimate tooth, 

 much worn. The anterior and posterior dental foramina are visible. 



PLATE vm. 



This is the first of a series intended to show each of the six teeth separately, and of then- 

 natural size. They are all from the lower jaw. The two first were removed from their sockets 

 in the jaw of the Calf Mastodon, represented Plate II. ; the third, from another specimen of 

 about the same age ; the fourth, fifth, and sixth, are teeth found separate from the jaw. 



The first tooth on the left hand in this plate is the first and smallest milk molar. That on 

 the right is the second and larger. 



The figure below is not one of the regular series, but is taken from the cranium in Plate IV. 

 and placed here for convenience. It is intended to show the appearance of a molar tooth in the 

 process of development. The crown is formed; the cavity below, or to the left of the crown, 

 shows the situation of the undeveloped fangs. 



These germs are the crowns of teeth without the fangs. They bear their proper number of 

 ridges and mammillae, and, when viewed from without, appear to be quite perfect teeth ; but, on 

 examining their internal surface, there is found to be a large, regular cavity, containing a number 

 of smooth projections, which correspond with the fissures or concavities on the outer side of the 

 tooth. There are no fangs, and the edges of the shell-like hollow are very thin. Before this 

 tooth can become useful, the fangs must be developed ; whence it happens that the cusps of the 

 mammilla? are not worn. In the growing animal one or more of these germs are usually found, 

 and more commonly of the ultimate tooth than any other. 



