347 



enamel is disposed. This occurs most particularly in a space in the an- 

 terior part of the surface. Here one deeply undulating line of enamel 

 forms the parietes of one wide and deeply indented compages of osseous 

 matter, occupying, as may be seen by the figure, the space of four or five 

 plates. It is very evident that this tooth could not, upon the decompo- 

 sition of the crusta petrosa taking place, divide, in this part, into detached 

 flat plates, as in the teeth of the recent and ^ of the common species of 

 fossil elephants. This structure is also observable in the fossil-tooth from 

 Wellsbourn, which has been already noticed. 



This extraordinary structure also exists in the curious and interesting 

 specimen, Plate XX. Fig. 7. This tooth, with the locality of which I 

 am unacquainted, having purchased it at the sale of Mr. Forster's collec- 

 tion, is one, which must have been on the point of being excluded from 

 its alveolus; the plates on its fore part being entirely worn away, and, of 

 those on the posterior part, some very shallow portions only remaining. 

 These, however, are sufficient to show, that the plates in this tooth were 

 formed and arranged in a similar mode with those of the preceding tooth. 



In the fore part of this tooth, from which the plates have been removed, 

 is a very smooth and polished surface of a thin coat of the crusta petrosa. 

 This is, indeed, so thin, that at the root of the small projecting piece of 

 enamel, in nearly the middle of the tooth, a small part is discoverable, 

 where the crusta petrosa itself is worn through, and a portion of the sub- 

 stance of the root itself has been acted upon. Behind this are two de- 

 tached bands, linearly and transversely disposed. Just above the upper 

 part of one of these commences a line of enamel, which proceeds in un- 

 dulations for the space of two plates, through half the width of the sur- 

 face, the remaining half being filled up by two separate terminations. 

 The line of enamel then passes on, by deep undulations, to the back part 

 of the tooth, filling up the space of three more plates. This peculiarity of 

 structure will however be better understood from the figure, than it can 

 be from even the most exact description. 



This specimen is particularly interesting, from the circumstance of its 



