Gh. XVII.J 



MOLLUSCA, BRYOZOA, SPONGES. 



329 



Europe, a single representative only (fig. 312) has been discovered in 

 the white chalk of England. 



Smmm 



Eschara distieha. 



a. Natural size. 



b. Portion magnified. 



"White chalk. 



Fie. 317. 



Fig. 318. 



Escharina oceani. 

 a. Natural size. 

 1). Part of the same magnified 



White chalk. 



Ventriculites radiatus. 



Mantell. 



Syn. Ocellaria radiata, 



D'Orb. White chalk. 



Fig. 320. 



Fig. 319. 



A branching sponge in a flint, from the white chalk. 

 From the collection of Mr. Bowerbank. 



Siphonia pyriformis. 

 Elackdown beds. 



