254 Memoir ripov living midjhssil Eltphunis. 



As to the texture, we have seen a little before, that it is ab- 

 solutely the same in all the species, and the tusks of the nias- 

 lodonuis are not distinguished in this respect from those of ele- 

 phants. It only rem'ains therefore, to compare their curvature. 



Several fossil tusks have only one very common curva- 

 ture : such are the tusks in our Museum. 



But there is a sufficient niunber of them, the curvature 

 of which is much greater than we sec in the tusks of living 

 elephants. The shape approaches a semicircle^ or the half 

 of an ellipsis divided by its small axis. 



There are four fossil tusks described : — that of Messer- 

 schmidt, in the Philosojjhical Transactions; that in theStras- 

 burg cathedral, according to Herjnan ; that of the church of 

 Halle, in Suabia, according to HoiTman and Bevschag; and 

 that of the cabinet of Stutgardt, according to Authenrieth 

 and ScPger. This striking, resemblance of four of the most 

 entire fossil tusks we know, in a point which distinguishes 

 them from the tusks of living elephants, is worthy of remark. 



Soviie have thought of making a distinct character from 

 this circumstance : but it may be easily inferred, that this 

 great curvature depends only upon the length of the tusks, 

 where this circumstance has been remarked. 



The part of the tusks once made being no longer subject 

 to change, each increase in length will also be an augmenta- 

 tion in the number of the degrees of the arc it describes. 



It is thus that the incisor teeth of hares, when theopposite_ 

 ones are broken, curl up into a spiral direction. 



It is prbper, hov.evcr, to observe, that a tusk from Africa, 

 in our Museum, although six feet long, is by no means so 

 crooked as the four we have quoted. — There are also some 

 fossil teeth turned like a still-worm, as we see in living ele- 

 phants. Pallas quotes one from the Petersburgh cabinet*. 

 There is one also, but less twisted, in the Stockholm cabinet, 

 of which jNI. Oucnsel sent me a drawing. 



Thus tusks can establish no certain character, either 

 among the living species, or beLV\'een the latter and the fossil 

 &pecics. - 



* Nov. Com. .\in. 

 [To he conliniieiL] 



XXXVMI. Me- 



