292 Mr Connell's Analysis of the 



resemblance in composition between the recent and the fossil 

 scales. 



Scales, Scales, 



Lepisosteus. Megalichthys. 



Phosphate of Lime, .... 46.20 50.94 



Carbonate of Lime, .... 10. 11.91 



Animal Matter replaced in the Megalichthys by Hydrated 



Siliceous Matter, . . . . 41.10 36.58 



Phosphate of Magnesia and Alkalies, small quantities. 



97.S 99.43 



I am happy in being able thus to add something like chemi- 

 cal evidence in support of the alliance between the sauroid fish 

 of Burdiehouse and its supposed living type. 



I have found also that the scales adhering to coal discovered 

 by Lord Greenock at Craighall, and of which his Lordship was 

 so kind as to give me some specimens for chemical examination, 

 leave, when acted on by acids, a siliceous skeleton, which doubtless 

 has been supplied by substitution for animal matter in the same 

 manner as in the other, although to a less extent. I have not 

 yet had time to complete an analysis of these scales, but shall 

 communicate the result to the Society when obtained. I hope 

 to be able to communicate at the same time some other analyses, 

 farther illustrative of the question how far the chemical nature 

 of fossil scales may be capable of throwing light on the character 

 of the animals from which they have been derived. 



It is worthy of remark, that the manner in which the animal 

 matter of the scales of the Megalichthys has been replaced by 

 siliceous matter, is very conformable to that in which, according 

 to the views of Von Buch, shells have in certain instances been 

 sihcefied. According to that eminent geologist, it is only the ani- 

 mal matter between the calcareous layers of the shell which is 

 converted into siliceous matter, the calcareous layers being usually 

 thrown off altogether, although sometimes included within the 

 flinty substance, but never themselves sihcefied. 



In like manner in the scales, the phosphate and carbonate of 



