220 The Kent's Hole Machairodus. [April, 



The under jaw of Mach. neo. is considerably smaller than 

 that of the lion, and only a little longer, but at the same 

 time decidedly much narrower than that of the jaguar; but the 

 palate is much broader than that of the lion or tiger, at 

 least in front. The following measurements, in inches, of 

 the length of the under jaw, from the front edge of the tusk 

 to the back part of the edge of the neck, in some of the 

 larger Felidce and Mach. neo. may be of interest here : — 

 Cave-lion (Felis spclcza), n'4; Lion (F. Ico), 0/4; Tiger 

 (F. tigris), 8'3 ; Ounce (F. onca), yg ; and Mach. neo., 8*7. 

 The under jaw of Machairodus is known with certainty by 

 the forestanding edge-comb of the chin on each side, beside 

 which lies the great canine of the upper jaw. It seems to 

 indicate that the point of this tusk could not be hidden 

 under the lips when the mouth is closed, though the upper 

 lip was much broader and more fleshy than that of the 

 existing Felidce. 



The Buenos Ayres skull contains three upper and two 

 lower molars on each side. The foremost of the lower 

 series is wanting, and there is no trace of an alveolus. The 

 number and formation of tubercles on them is quite like 

 those of the' feline animals. 



The following are the dimensions of the upper canine : — 

 Length of the crown 5 inches, of the gum 1 inch, of the 

 root 4*5 inches ; total length in a straight line 10*5 inches. 

 The under tusk is surprisingly small in comparison, and 

 scarcely larger than the upper outer incisor. Both the 

 upper and lower canines are devoid of the longitudinal 

 furrows which the tusks of the real Felidce possess — two 

 upon each side of the upper, and one on the outer side of 

 the lower. 



The external upper incisors, like the lower canines, are 

 conical, bluntly pointed, slightly bent inwards, and bluntly 

 three-cornered. In the Felidce the outer incisors, especially 

 in the upper jaw, are much larger than the inner ones, 

 which are of equal size ; whilst in the lower series a differ- 

 ence of size is perceptible between the inner and the middle 

 ones on each side. In Machairodus neogaeus the difference 

 of size between the three on each side, in each jaw, is much 

 more considerable, and the gradual increase from inwards 

 to outwards is not to be mistaken. The teeth of the upper 

 and lower jaws also harmonise more with each other both 

 in form and size — each one of the lower series being a little 

 smaller than the corresponding incisor in the upper. The 

 following measurements of the crowns clearly show the 

 proportions of the several teeth : — 



