140 HISTORICAL PALAEONTOLOGY. 
fan-like or funnel-shaped form, which grew attached by its 
base to some foreign body. ‘The frond consists of slightly- 
Fig. or. — Fragment of 
Ceriopora Hamiltonensis, of 
the natural size and enlarg- 
Fig. 90.—Fragment of Clathropora intertexta, of the ed. Devonian, Canada. (On- 
natural size and enlarged. Devonian, Canada. (Original.) 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 
ginal.) 
Fig. 92.—Fragment of Fenestella magnifica, Fig. 94.—Fragment of Fenestella 
of the natural size and enlarged. Devonian,  cvébrosa, of the natural size and enlarg- 
Canada. (Original.) ed. Devonian, 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 
