292 Mr ConneE u's Analysis of the 
resemblance in composition between the recent and the fossil 
scales. 
Scales, Scales, 
Lepisosteus. Megalichthys. 
Phosphate of Lime, J ‘ ; ¢ 46.20 50.94 
Carbonate of Lime, s 10. 11.91 
Animal Matter replaced in the Meeatehth ye by Hyder 
Siliceous Matter, : ‘ 41.10 36.58 
Phosphate of Magnesia and Alkalies, andl quantities. 
97.3 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matter of the scales of the Megalichthys has been replaced by 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 Bucu, shells have in certain instances been 
silicefied. 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 silicefied. 
In like manner in the scales, the phosphate and carbonate of 
