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 carduus of Ellis ; but it does not appear that its surface 

 was inuricated, 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. 



