Analijsis of the Scales of the Fossil GcanaL 253 



cal examination, with the .view of comparing the result with 

 that afforded by fossil scales of fishes. 



The calcareous slab from which the specimen in question 

 was taken, contained several of these gavial scales, the largest 

 of which were about two inches square. Their appearance 

 corresponded closely with the account of them given by Cu- 

 vier in the following extract, particularly as respected their 

 great thickness, and the cavities on their surface. " They dif- 

 fer from those of living crocodiles more than any other part of 

 the skeleton, and this crocodile of Caen was undoubtedly the 

 best mailed of tlte whole genus. The scales are very thick, 

 rectangular, thinner towards the edge, and their whole external 

 surface is hollowed into little hemispherical cavities, of the size 

 of a lentil or pea, and pressed against one another."* The 

 scales examined were not carinated, and had probably belonged 

 to the sides of the animal. Their structure was partially lami- 

 nated ; but they had also acquired a texture somewhat crystal- 

 line, possessing a fine-grained fracture, a certain degree of 

 translucency on the edges, and a hardness equalling that of 

 fluor, and much exceeding that of any fossil fish scales which 

 I had ever seen. 



The methods of analysis were the ordinary ones applicable to 

 such a case, and were the same as those formerly pubhshed. 

 The constituents of the Caen scales were found to be 



99.02 



One or two considerations are suggested by this result. 



In tliey?;*^ place, It is manifest, that these scales w-ere origi- 

 nally of the nature of bone, and, in all probability, entirely ana- 

 lofTous to the osseous scales of fishes ; and hence the presence or 

 absence of bone-earth in such fossil relics can be of no service 



* Ossemens I'ossiles. torn. v. part IL p. 139. PI. VH. liq. 41. 



