58 THE OPEN BOOK OF NATURE 
Michelinia favosa Amplexus coralloides Lithostrotion affine 
(Carboniferous). (Carboniferous). (Carboniferous). 
Holocystis elegans Trochocyathus 
(Cretaceous). conulus _(Kocene). 
(Cretaceous). 
Fie. 10.—Somz Fossti Coratrs. 
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