xvi.] FORAMINIFERAL LAND. 271 



bed of softish limestone. The great bulk of this calcareous 

 rock would be made up of entire, or fragmentary, Globi- 

 gerina and Orbulina shells ; but it would contain, in addi- 

 tion, other Foranimifera, shells of shellfish, remains of 

 starfishes, and sea-urchins, and of such other animals pro- 

 vided with hard skeletons, as are now living in the Atlantic. 

 It would, in fact, be a highly " fossiliferous " limestone 

 with more or less silex, in the shape of Radiolaria 

 skeletons and sponge spicules, scattered through its mass, 

 and would constitute an element of no small magnitude 

 and importance in the composition of the earth's crust. 



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