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quently twenty-four. M. Cuvier figures one found in the forest of Bondy, 

 in which there are twenty-two. A second distinctive character, according 

 to M. Cuvier, is, that the lines of enamel are thinner, and less scalloped 

 or crenulated, in the fossil, than in the others, he having only noticed one 

 exception. A third character is, he thinks, yielded by the much greater 

 absolute, as well as proportional, width of the fossil, this being in the 

 proportion of eight to six. 



The specimens which I possess do not, except as to the greater degree 

 of thickness of the teeth, exactly accord with these observations of M. 

 Cuvier. This is, I believe, in consequence of my happening to possess 

 some fossil teeth, of different species, from those in the possession of that 

 gentleman, or from those which I have seen described. 



As to the greater thinness of the plates in the fossil than in the recent 

 species, this is, 1 think, undoubtedly the case, not only with the common 

 fossil teeth, as appears in three or four detached teeth from Essex, and in 

 one which is still retained in its alveolus, in a jaw nearly perfect; but it 

 is also the case with the undulating plates of two other teeth, of which I 

 shall soon have occasion more fully to speak. In the one which is still 

 retained in the jaw, seventeen plates are seen in ten inches extent of sur- 

 face, all of which were in use at the death of the animal : and, in the two 

 last-mentioned, lamellae equal to twenty plates exist in a length of tritu- 

 rating surface of six inches and a half. One of these is represented Plate 

 XX. Fig. 8. In a fragment of. an upper tooth from Germany, in the 

 length of five inches, are contained only eight lamellae. 



But the specimen which offers the strongest exception to the greater 

 degree of thinness of the plates existing in the fossil teeth being admitted 

 as a general rule, is represented Plate XX. Fig. 6, being a tooth of the 

 left side of the upper jaw, which I purchased from Mr. George Hum- 

 phries, in the sale of the Calonnian Museum, and which is described as 

 having been found in Staffordshire. 



This curious fossil differs materially, not only from the teeth of the 



