45 
The lithostrotion, according to Dr. Woodward, is all found on the 
rocky cliffs, about two miles from Tenby, towards Milford, in Pem- 
brokeshire. But it is also found both on the river shores, and on the 
mountains in several other parts of Wales: and in Lancashire, Cheshire, 
Yorkshire, and in several other parts of England and Scotland. It is also 
found in different parts of Germany. 
From the similitude of this fossil to a spideFs web it might with pro- 
priety derive a name, had not a name, thus derived, been already applied 
to a coral of a different species. Perhaps the other epithet given to it 
by Volkmann would not be considered as very inapplicable ; in which 
case it might be named madrepora vorticalis. ' 
Da Costa, who distinguishes by the term marmoroidcB those stones 
which, although they have all the physical and chemical properties of 
marble, are not found in continued strata, but are only found in loose 
independent masses, lodged in strata of other substances, has named 
the stone which this coral has formed marmoroides colimnaris stellatus, 
lithostrotion dictus. 
One of the fossil corals which has been considered as belonging to 
this family, is the lapis arachneolitlii, or spider-stone, respecting which 
the celebrated Bruckman wrote an ingenious disquisition in a letter to 
his friend, the learned Ritter.* From this it appears that stones, which, 
from their marks and form, bore a resemblance to the body of a spider, 
from which the head and legs had been removed, were frequently 
employed in some parts of Germany as a powerful charm for the cure 
of all kinds of haemorrhages. These stones, according to the received 
vulgar opinion in those parts, were supposed to have been generated 
and voided by a spider. It was also imagined by the country people, 
that every spider, remarkable for its magnitude, contained one of these 
stones : to obtain the expulsion of which, the spider was to be enclosed 
* Fr. Ernesti Bruckmanni, de Fabulosissimse Originis Lapide Arachneolitho dicto 
Epistola. 1722. 
