174 



HISTORICAL PALEONTOLOGY. 



from the fact that almost all the varied types of which it is 

 composed disappeared utterly before the close of the Carbon- 



Fig. ii6. — Corals of the Carboniferous Limestone, a. CyatJw/>hyUii}nparacida,s\iovf- 

 ing young corallites budded forth from the disc of the old one ; a', One of the corallites 

 of the same, seen in cross-section", b. Fragment of a mass of Lithostrotion irregulare ; 

 h\ One of the corallites of the same, divided transversely ; c. Portion of the simple cj'lin- 

 drical coral of A viplexus coralloides ; c' , Transverse section of the same species ; d, 

 Zaphrefitis vennicularis, showing the depression or "fossula" on one side of the cup; 

 e. Fragment of a mass of Syringopora ratnjdosa ; f, Fragment of CJustetes tuniidtis; /', 

 Portion of the surface of the same, enlarged. From the Carboniferous Limestone of 

 Britain and Belgium. (After Thomson, De Koninck, Milne-Edwards and Haime, and 

 the Author.) 



iferous period. In the first marine sediments of a calcareous 

 nature which succeeded to the Coal-measures (the magnesian 

 limestones of the Permian), the great group of the Rugose 

 corals^ which flourished so largely throughout the Silurian, De- 

 vonian, and Carboniferous periods, is found to have all but 



