PAL.EOTHERIUM. 321 



enamel, from which the two oblique peninsular folds are 

 continued into the body of the tooth, corresponding with 

 the primitive depressions on its surface, displayed by the 

 germ of the molar here described (fig. 112). 



Fig. in. Fig.lU. 



First premolar, nat. 



Much worn upper molar, nat: size. Palieot/ierium 



size. Palceotherium crassum ; medium ; Binstead, 



Binstead, Isle of Wight. Isle of Wight. 



The opposite condition of the grinding surface is shewn 

 in a molar tooth of a Palseothere (fig. 113), from the lower 

 freshwater formation at Binstead; the valleys, a and 5, 

 are both reduced to islands of enamel. The specimen is 

 in the Museum of the Geological Society. 



The first premolar (fig. 114) is the smallest and most 

 simple of the series : its crown is narrower transversely ; 

 the two outer depressions are shallower : there is a longitu- 

 dinal depression along the inner side of the grinding sur- 

 face, bounded behind by a prominent ridge : the unworn 

 crown forms an elongate cone ; but the surface is soon 

 reduced to an uniform flat tract of dentine, in which state 

 this tooth is commonly found. The specimen figured, 

 from the Binstead quarry, is from a young animal. In the 

 second premolar the internal fold is nearer the anterior 

 border of the crown than in the third and fourth pre- 

 molars, which diifer from the true molars only by a slight 

 inferiority of size. 



