290 ON THE FOSSIL BONES OF PACHYDERMATOUS QUADRUPEDS. 



the gum, and has some few additional plates concealed in the socket. 

 The observations we have just made on the succession of the jaw-teeth 

 of elephants is fully explanatory of these appearances, as being con- 

 nected with the age of the animal. 



Hence we cannot consider the thinness of the plates as forming so 

 general a characteristic of the fossil elephant as the size of its teeth, 

 and the shape of its jaws and head. Nevertheless, the size alone of its 

 jaws is sufficient to identify them, because it is much more constant 

 and unvarying. 



In addition to this, there are some specimens wherein this difference 

 of thickness is more apparant than real, and depends upon the age of 

 the tooth. The last plates of each tooth are thicker than the first, and 

 when the anterior part of a tooth has been decayed, and the posterior 

 part very much worn down, it must then exhibit plates much thicker 

 than it did at first. 



This has been the case with some of the teeth I have mentioned. 



As for the fossil molares of elephants which have come from North 

 America, they frequently present a singular appearance; the alternat- 

 ing lines of enamel, of cement, and of bony substance, may there be ob- 

 served not only at the crown, but on the two lateral surfaces, even as 

 far as the roots, which is solely owing to the teath being worn at the 

 sides, and serves to show that they had been for a long time agitated 

 by the waves, previous to their being deposited where they have been 

 found. (See the figures we have given of two of these teeth, ])l. 15, 

 Jigs. 9 and 11). 



It remains for us to examine if fossil teeth of elephants have not 

 been found bearing a greater affinity to those of the African than the 

 Indian species. 



I feel bound to state that I have not as yet met with a specimen of 

 the kind. 



M. Humboldt, indeed, mentions in a letter inserted in the Annals of 

 the Museum, p. 337, that he found near Santa Fe an immense quan- 

 tity of bones of elephants, "as well of the species of Africa as of that 

 of Ohio ;" but a more profound investigation has since demonstrated, 

 as we shall see hereafter, that all these bones belonged to a peculiar 

 species of mastodon. 



M. Autenrieth has also informed me that he saw at Philadelphia 

 some teeth which appeared to him to have a closer affinity to those of 

 the African than the Asiatic elephant; but M. Barton has since most 

 positively informed me that these teeth had been brought from Africa. 



For my part, I have never seen more than two specimens which 

 were calculated to create the least doubt in my mind. 



One of these was in the museum of Mr. Ebel, at Bremen, and the 

 second is in our museum. They are both impaired, and of a greyish 

 colour. I have not been able to ascertain whei'e that of Paris has been 

 found. Mr. Ebel informed me that that belonging to him came from 

 Eichstedt. If this latter origin be correct, it will be necessary; to ad- 

 mit the existence of a second fossil species ; but as it frequently 

 happens that they bring us teeth found near the surface of the 

 soil in Africa, more or less impaired by the action of the elements, 

 I would not venture to establish a fact of such importance upon a 



