36 TABULATE CORALS. 



Genus. Geological range. 



Romingaia, Nich. ( = Quen- \ ^ Devonian. 

 stedtta, Rominger), j 



r. T J { Carboniferous and Permo-Carbonifer- 



Stenopora, Lonsd. . . \ /-,\ -r, ■ , 



^ { ous ; (?) Permian also. 



Billingsia^ De Koninck, . . Devonian. 



Laceripora, Eichw. (imperfect- \ _ ^^^^^^ g-j^^j^,^ ^^^^ Carboniferous. 



ly known), j 



Nodidipora, Lindstr. . . . Upper Silurian. 



An examination of the above list shows that of the twenty- 

 two genera placed in the FavositidcB no less than twenty are 

 Palaeozoic ; so that this group of Perforate Corals enjoyed, 

 therefore, a great extension at this early period. Koninckia 

 is the only Cretaceous genus, and Favositipora the only recent 

 one ; and both might find a place in the PoiHtidce, near Alveo- 

 pora. Moreover, the group attained its maximum develop- 

 ment in Upper Silurian and Devonian times; very few types 

 survive into the Carboniferous period ; and perhaps the only 

 one existing in the Permian is Stenopora. Indeed the great 

 abundance of these Palseo-Perforate Corals in the Devonian, 

 and their very scanty representation in the Carboniferous, may 

 be taken as one of the strongest of the palseontological proofs 

 that the periods so named are geologically distinct. Lastly, the 

 almost total absence of examples belonging to the Favositidce 

 in Secondary and Tertiary deposits affords an indication that 

 the family is more than a mere sub-group of the now widely 

 distributed Poritidce. 



