1841.] Note on the Fossil Jaw sent from Jubbulpore. 623 



What I mean, however, will be best shewn by the sketches in the 

 plate, where — 



A, is the Fossil : the angle at a being 110°. 



B, Fossil head from Siberia (Cuvier Ossemens, F. pi. viii. fig. 1.) an- 

 gle at a, 1 22°. 



C, first Fossil Scull, Mus. As. Soc. perhaps Mastodon Elephantoides, 

 angle «, of which one branch is the chord of the arc formed by the 

 molars, 136°. 



D, First recent Scull, No. 1 of the foregoing measurements angle a, 

 100°. 



E, Large recent scull, No. 3 of foregoing measurements angle a, 95°. 

 In the plate the fossil A, with C D and E are drawn to the same 



scale, in B. from Cuvier there is no scale mentioned. 



I have already alluded to the number of the plates in the incisor or 

 horizontal part ; in the posterior part of the jaw I should mention that 

 they are separated by a soft, white, powdery mass, which easily gives 

 way (much like chalk) to the knife ; the plates themselves are hard, 

 bony-like, and brittle, their length is about six inches, and on the 

 most perfect side there are 21 plates in a space of 12^ inches, all 

 perfectly defined. In a recent scull I find 13 plates in a distance of 9 

 inches, which would give but 18 for 12^ inches, and they are all loose, 

 and so soft, as to yield to a slight touch of the tool. In a word, our fossil 

 seems to have had these as true teeth, and not as germs, as in the 

 modern elephant. 



4. The transverse breadth of the jaw. — As this dimension is fortu- 

 nately obtainable, I have thought it should not be neglected, as tending 

 to throw light upon the question of the animal's age. As before men- 

 tioned, it is measured at that part of the incisive bone, where the arch 

 rises. It should be remarked, that not being taken from a fixed point, 

 it is, in so far, an approximative measurement depending on the accu- 

 racy of the eye in fixing upon nearly the same part of the arch as that 

 which is taken in the fossil. The comparative dimensions are as 

 follow : — 



Breadth of the jaw. 

 Inches. 



The Fossil, ... 10.4 



A. First Fossil Scull as before, 11. 1 



B. Second, imperfect. 



