322 



PALJ30THERIUM. 



Fig. 115. 



PAL^OTHERIUM CRASSUM. 



THE molar teeth of the lower jaw are, as is usual in the 

 herbivorous Mammalia, narrower transversely, arid of a 

 more simple structure than those to which they are opposed 

 above. In the present genus they are seven in number on 

 each side of the lower jaw : the first is the smallest, and has 

 a simple compressed conical crown : the rest have their 

 outer part formed of two half cylinders, except the se- 

 venth, which has a third smaller semi-cylindrical lobe. 

 Of such a tooth, which was obtained from the Seafield 

 quarry, Isle of Wight, two views of the recently formed 

 crown are subjoined (fig. 115) : a is the outer side, shew- 

 ing the form above described ; b is the 

 inner side, shewing the longitudinal 

 depressions which penetrate the outer 

 lobes or convexities. This tooth, which 

 is rather less than the corresponding one 

 of the PaleEotherium crassum, figured by 

 Cuvier, (' Ossemens Fossiles,' 4to, 1822, 

 torn. iii. pi. 1, ^,) must have belonged 

 to a young animal. It had probably 

 not cut the gum ; certainly not come 

 into use, for the margins of the crescentic 

 Last lower molar, nat. summ it s o f the three lobes are unworn. 



size. Palceotheve. Eocene 



marl, Isle of Wight. I n the grinding surface of the tooth 



(fig. 116), which is the fifth of the 

 molar series of the lower jaw, and the 

 first of the three true molars, the two 

 crescents are united by a continuous 



Fifth lower molar, nat. ----- j- , 



size. Paiaotiierium eras- tract or dentine, the intermediate wall 



sum ; Binstead, Isle of n i i i j 



Wi | lt _ or enamel having been worn down. 



Fig. 116. 



