37 
LETTER VIII. 
OTHEE MADREPOEES, NOT PERHAPS KNOWN IN A FOSSIL STATE...- 
MADREPORA FAVOSA. ...MADREPORA RETEPORA....M. ANANAS, &C. 
M. FOLIOSA, &C ASTROITES LITHOSTROTION OF LHWYDD 
SPIDER STONE OF BRUCKMAN. 
W E now proceed to make inquiry respecting the fossil remains of those 
madrepores which are composed of many stars. The first of these in 
the Linnaean order of classification are those which are concatenated and 
formed by disjoined stars, with continuous lamellae. 
These are madrepora pileus, m. cristata, m. lactuca, m. Jicoides, m. 
acerosa, m. lichen, m. agaricites, m. elephantotns, m. Crustacea, m. in- 
crustaus, m. exesa, m. jUagrana, m. natans, m. anthophyllum: but I have 
not been able to discover any of the remains of these in a mineralized 
state. 
Those madrepores, which are distinguished as being conglomerated, 
the stars of which are united together, form the next objects of our 
inquiry. Of these, madrepora labyrinthica, which has no stem, and 
the stars of which are divided by obtuse sutures, extended in laby- 
rinthian windings, I have more reason to suppose may exist in a 
mineralized state. From the form of this coral, which is generally 
approaching to a hemisphere, and from its upper surface, which is 
marked with convolutions much resembling those of the brain, it has 
acquired the common appellation of brain-stone. This coral is chiefly 
found in a recent state on the rocks which surround the West-India 
islands. But I have repeatedly seen among the bowlders with which 
some of our streets are paved, and which I am informed are chiefly 
