994 THE MEDALS OF CREATION. Cuap. VII. 
and full of large pores. When completely silicified the struc- 
ture can only be detected by fracture, but occasionally the 
sponge appears to have been saturated with liquid chalk 
before it was enveloped in the flint; and as it is coated with 
calcareous matter, it may be detached from the nodule 
entire.* 
Lien. 69. CoRAL, AND SPONGITES. 
Chalk. Sussex. 
Fig. 1—PETALOPORA PULCHELLA. Upper figure x x: lower figure, nat. 
Chalk near Chichester. (Mr. Walter Mantell.) 
2.—SPONGITES CLAVELLATUS. A branch in the cavity of a flint. 
South Downs. 
3.—SrpHONIA Morris1Ana. (G. A.M.) A transverse polished sec- 
tion of a pebble. Brighton Beach. 
A smaller ramose spongite, with numerous short clavate 
protuberances, is often met with in the flints of Sussex and 
Wilts ; a branch is figured in Lign. 69, fig. 2.T 
* In this manner I obtained the beautiful specimen (now in the 
British Museum) figured in my Foss. South Downs, tab. xv. fig. 11. 
A branch of this species is represented Pict. Atlas, pl. xxxix. fig. 12. 
Spongites lobatus (sp. Fleming) is figured Pict. Atlas, pl. xxxix. 
fig. 6. 
+ This spongite is named Polypothecia clavellata, in Miss Benett’s 
Wiltshire Fossils. 
