PLATE XIX. 
Fig. 1. A sketch of the part of the recent pentacrinus described by Mons. Gnettard. 
2 . The superior part of a pentacrinite, found at Pyrton Passage, Gloucestershire. 
Ihis sketch is copied from the fifty-second volume of the Philosophical 
Transactions. 
3. Part of a tunnel-formed alcyonium, filled with, and surrounded by, the green 
sand of Pewsey, in which it was found.* 
* Not having been tavoured with this specimen in time, I was unable to notice it in the 
body of the Work, or introduce it in the earlier Plates : and not having it, therefore, in my 
power to compare the P ewsey tbssils with that represented in the Frontispiece, I was unable 
to determine whether the information which I had received respecting the locality of the 
latter fossil was correct or not. Comparison now enables me to state that the alcyonite in 
the Frontispiece appears to agree exactly in structure with the Pewsey alcyonites ; but that 
the latter have evidently undergone a much more considerable chemical change than the 
former. The degree and kind of chemical change which the latter fossil has suffered 
seems, indeed, to authorize its being considered as a French fossil. 
