FOSSIL SEA-MATS. 221 



ture, each surface of this convoluted and radiated 

 structure showing the latticed appearance of a sea- 

 mat. This is Fascicularia aurantium. Other common 

 kinds (about which Professor Busk wrote a mono- 

 graph for the Palaeontological Society) are several 

 species offfornera, of which the most beautiful, perhaps, 

 is H.reteporacea; several species ofAtveotaria, the finest 

 and largest being A . semiovata ; of Eschar a y and Celle- 

 pora. Some of the latter species are branched and 

 resemble corals ; others, as Cellepora edax, have crept 

 over, covered, and suffocated the inhabitants of uni- 

 valve shells. Hydractinia is also found in the fossil 

 state in the Coralline Crag, covering shells in a similar 

 manner. Other abundant sea-mats are various species 

 of Lepralia (found covering the interiors of empty 

 bivalves), Heteropora, and others which the collector 

 will not fail to gather about Orford and Aldborough, 

 in greater abundance than his powers to remove them 

 will prove available. 



