in the Neighbourhood of Edinburgh. 221 
The two different characters of mineralization are exhibited in the following 
Table. 
Fossil Scales of the Megalichthys contain Thorny Rays of the Gyracanthus contain 
Carbonate of Lime, . : 11.91 Carbonate of Lime, . ; $3.86 
Hydrated Siliceous Matter, 36.58 Siliceous Matter, ‘ ‘ 10.22 
48.49 44.80 
These observations have been suggested by the important analysis of Mr Con- 
NELL. But he is far better qualified than myself to enter into questions relative to 
the chemistry of geology. 
I shall, lastly, make some few remarks upon these. large rays, as they are found in 
other localities. 
It would appear that the large bony rays of the Gyracanthus are not confined to 
the limestone of Burdiechouse, as I have seen specimens of them collected from the 
argillaceous shale of Fifeshire. Similar relics have also been discovered in Northum- 
berland. 
In the next place, large bony rays, referable to other placoidian fish, appear in 
the shale of the coal-fields of Glasgow; they are likewise found in limestones of ma- 
rine origin, as in the mountain-limestone of Ashford, from which locality I procured 
them during the course of the last summer. Dr Simpson of Bathgate found a sili- 
cefied organic substance in a mountain-limestone of marine origin, which, if it had 
not been in so old a deposit, I should have taken for a belemnite. It was obtained 
from Kate Shield’s or Crawford’s quarry, near Bathgate. M. Acassiz thinks that it 
indicate an interior cavity (from which the organic matter must have been removed) 
of one of these large rays. 
SECTION XV.—THE COPROLITES OF THE LIMESTONE OF BURDIEHOUSE. 
From the numerous relics of small and immense finny ani- 
mals discovered in the quarry, it cannot surprise us to find that 
foecal remains should occur in an abundance, rivalling perhaps in 
this respect the particular locality which very early excited the 
attention of Dr BuckLanp, and to which he has given the name 
of the Cloaca maxima of Gloucestershire. 
In inspecting the very exact figures of the coprolites which 
have been published in the excellent memoirs of Dr Buckianp on 
this subject, it might be expected that we should find these 
shapes abundantly developed in the limestone of Burdiehouse ; 
but the contrary is the fact. The peculiar forms of the foecal 
contents of the intestinal canal must, from their aqueous submer- 
