67 
diluted muriatic acid, and was speedily dissolved, with effervescence. 
During the decomposition of this piece of marble, not the smallest 
filament of membranaceous substance became detached ; but, on the 
contrary, the newly-forming surface was as perfectly clean and smooth 
as if it had been a piece of primitive lime-stone : the black matter 
from which the marble derived its colour falling to the bottom of the 
vessel, during the solution of the marble. This powder being dried 
was projected on melted nitre and immediately produced deflagration : 
a circumstance which, with the form of the coral having been visible in 
the marble, shews the curious fact that a part of the colouring matter 
of the marble was an animal charcoal. 
In this class of fossils may be also placed the madreporite, Plate V. 
Fig. 5, from Steeple Ashton, which was presented to me by Mr. 
Herbert, of Bristol, whose kindness I have before had occasion to 
acknowledge. The perpendicular lamellae forming the star of this ma- 
dreporite, the periphery of which is not always circular, are connected, 
not only by short and partially disposed transverse plates, but by several 
series of larger horizontal plates, passing at the distance of a quarter or 
of half an inch, through the whole substance of the madrepore, and con- 
necting the perpendicular lamellae so firmly, as to give the appearance, 
in several parts, as if the perpendicular plates had been tied together by 
a tight ligature. Its form of ramification somewhat resembles that of 
the madrepora cardims of Ellis ; but it does not appear that its surface 
was muricated, or that the terminations of the lamellae were serrated, 
as is the case in that madrepore. Nor does there, indeed, appear to 
be any close resemblance between this fossil and any madrepore which 
has fallen under my examination. It appears to have been imbedded 
in a hard, close-grained lime-stone, of a pale yellowish colour, part of 
which, containing fragments of shells, and other marine remains, still 
adheres to the madreporite. The madreporite itself is formed of a 
spathose substance, strongly impregnated with iron ; as is the case with 
all the fossil madrepores found at Steeple Ashton. 
