FOSSIL FAUNA. 101 



PLATE XLI. 



A SiLICIFIED CUP-SHAPED SpONGE, FROM ToURAtNE. 



(Ckenendopora Parkinsoni, of Michelin. 

 Spongites Townsendi, of Mantell.) 



This beautiful plate of a petrified zoophyte allied to the Spongia, formed the frontispiece 

 to Mr. Parkinson's second volume. The fossil delineated is from Touraine in France, and 

 is one of the most perfect examples of this kind hitherto observed. It belongs to a group 

 of cup-shaped Amorphozoa, (as these organisms are now named by naturalists, from the great 

 irregularity of shape which they assume,) termed Ckenendopora. The original organic substance 

 is transmuted into silex, and the interstices are filled up with carbonate of lime. The same 

 species occurs in the greensand in the Yale of Pewsey in Wiltshire, and, I believe, also in the 

 white-chalk ; for many cyathiform flints from the South Downs appear to have the same 

 internalstructure. 



In the so-called " gravel-pits," near Faringdon, in Berkshire, — which are quarries of a loosely- 

 aggregated grit of the greensand, almost whoUy made up of the relics of shells, corals, amor- 

 phozoa, &c. — numerous sponges of this genus are met with. One beautiful species {Ckenendopora 

 fungiformis) has acquired, from its cup-like form, the local name of " petrified salt-cellar." ' 



' Wonders of Geology, vol. ii. p. 637 ; and Medals of Creation, " Excursion to Faringdon," vol. ii. p. 923. 



