PLATE VI. 
Fig. 1. A polished slab of Kilkenny marble, which derives its figures from one species of 
the madreporites which have been called Junci Lapidei. 
2. A species of madreporite of this kind from Derbyshire. 
3. A polished slab of marble, deriving its figured appearances from a smaller species. 
4. A madreporite, found in France, and frequently in Wiltshire, apparently the 
fossil described by Linnmus as Madrepora Arachnoides. 
5. A fossil madrepore which has been hitherto named Madrepora Pectinata. 
-6. One of the stars of the madreporite. Fig 4, magnified. 
7. A madreporite, the stars of which are very uncommonly formed. 
8. A madreporite bearing much of the appearance of the Madrepora Flexuosa, 
from Bristol. This fossil is coloured by the red ferruginous impregnation 
which so generally tinges the fossils of this neighbourhood. 
9. A madreporite of a very singular form and appearance, from near Ingleborough. 
10. A slice of marble from Switzerland, beautifully figured by a fossil madrepore, 
which has been named Madrepora Vermicular is. 
11. A madreporite which has been named Madrepora Fascicularis, and is remarkable 
for the frequency with which its transverse lamellae occur. 
12. Shews the general appearance of a polished section of chert, which is found fre- 
quently in some parts of Wiltshire. In this specimen a cast seems to have 
been formed, and the coral itself removed : the cast being afterwards impreg- 
nated with silex. 
13. Is the appearance observable in other specimens of this chert, where the calcare- 
ous part of the madrepore has remained, having undergone the silicious 
impregnation. 
