294 Mr Connell's Analysis of the 



able circumstances, — we shall obtain a substance almost identical 

 with the recent bones of the pike, and not differing much from 

 those of the cod. In this view, if we subtract from the calcare- 

 ous matter actually found in the fossil bones, a quantity equal to 

 that in the pike bones, and add the remainder to the siliceous 

 matter, we shall obtain the following comparison, shewing a sin- 

 gular resemblance. 



Phosphate of Lime, .... 



Carbonate of Lime, .... 



Animal Matter replaced in the Gyracanthus, by sili- ) „„ „„ 



ceous and calcareous matter, . I 



Phosphate of Magnesia, and Alkalies, small quantities. 



Bones. 



Bony rays. 



Pike. 



Gyracanthus. 



55.26 



53.87 



6.16 



6.16 



98.78 97.95 



I am aware, that if we adopt these last views, we must hold 

 either, 1 st, That the bony rays did not belong to a cartilaginous 

 fish, in which class I believe the Cestracion is ranked, for the 

 bones of cartilaginous fishes contain no bone earth ; or, 2d, That 

 the fin spines of cartilaginous fishes have a different constitution 

 from the other bones, a point which I do not know has been yet 

 investigated. 



Even when we view the composition of the coprolites im- 

 bedded in the limestone, in combination with that of the recent 

 fish-bones, we get something approaching to a coincidence. In 

 one of my analyses of these coprolites, the ratio of the phosphate 

 of lime to the carbonate of lime was about 8:1, and this does 

 not differ very much from that of those constituents in the re- 

 cent fish-bones, according to the analyses of Dumenil and Chev- 

 reul. In the other coprolite which I analyzed, there is, on this 

 view, an excess of about 5 per cent, of carbonate of lime, which, 

 of course, was derived from the matrix. The phosphate and 

 carbonate of lime form almost the entire mass of the coprolites 

 from the limestone, the only other constituent of consequence 

 being 2 or 3 per cent, of bituminous matter. 



