77 
to have been formed of detached parts, perhaps tubules, which have 
originated on the borders of the central cavity and have radiated 
regularly round it. Fig. 13 is a magnified representation of a section 
of one of the round bodies, by which the above description will be 
better understood. That these substances did not originally exist in 
a silicious state may be inferred from the appearance observable in a 
few of the striated parts, denoting their having suffered a degree of 
flexion : a circumstance which could not have occurred if they had 
been in a hard and rigid state. 
To what kind of substance this stone is indebted for its origin, is 
not possible perhaps at present to say. It is admitted in this place, 
in consequence of the resemblance it bears in some respects to the 
preceding specimens; and with the hope that information respecting 
it may be, obtained, from the remarks made on some more illustrative 
specimen. 
Some of the extraordinary circumstances which have arrested our 
attention, whilst examining into the nature of fossil corals, now demand 
a few general remarks. You cannot but have observed how completely 
I was foiled, in my attempt to preserve a parallel between the fossil 
corals which I have particularized, and the several corals which are 
enumerated in the Systema Naturce of Linnaeus. Indeed, so little could 
this parallel be preserved, so little agreement could be traced between 
the recent and the fossil corals, that I find myself under the necessity 
of acknowledging that I am not certain of the existence of the recent 
analogue of any really mineralized coral. 
This dissimilarity between the creatures of this and the creatures of 
the former world is a circumstance which appears to be so inexplicable, 
that I can only admit it, without attempting to account for it. It how- 
ever furnishes us, I think, with a strong argument against that theory, 
which supposes the changes which this planet has undergone are all 
attributable to the constant, regular, and gradual processes of nature. 
