146 



HISTORICAL PALEONTOLOGY. 



fan-like or funnel-shaped form, which grew attached by its 

 base to some foreign body. The irond consists of slightly- 





Fig. 90. Fragment of Clathrof>ora intertexta, of the 

 natural size and enlarged. Devonian, Canada. (Original.) 



Fig. 91. Fragment of 

 Ceriopora. Hamiltonensis, of 

 the natural size and enlarg- 

 ed. Devonian, Canada. (Ori- 

 ginal.) 



diverging or nearly parallel branches, which are either united 

 by delicate cross-bars, or which bend alternately from side to 

 side, and become directly united with one another at short 

 intervals in either case giving origin to numerous oval or 



F : g. 92. Fragment of Fenestella magnified, 

 of the natural size and enlarged. Devonian, 

 Canada. (Original.) 



Fig. 93. Fragment of Refepora 

 Phillifisi, of the natural size and 

 enlarged. Devonian, Canada. (Ori- 

 ginal.) 



Fig. 94. Fragment of Fenestelfa 

 cribrfta, of the natural size and enlarg- 

 ed. D.-vonian, Canada. (Original.) 



oblong perforations, which communicate to the whole plant- 

 like colony a characteristic netted and lace-like appearance. 

 On one of its surfaces sometimes the internal, sometimes the 

 external the frond carries a number of minute chambers or 



