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called the florets, seems formed without sufilclent room or 

 opening for it to protrude: but we presume that, although a 

 Coralline, it may have the power of opening the larger 

 segment when fresh, which a coriaceous substance natu- 

 rally admits of; so that the larger valve is a kind of door, 

 and is a strong characteristic of the species, although it is 

 sometimes much obliterated. We are not sure that this 

 has been figured at all, as the segment which is so re- 

 markable does not appear to have been noticed. It may be 

 worthy of observation here, that in some instances the 

 coriaceous substance which covers the darker branches all 

 round, and protrudes, as at the right hand figure, often 

 appears quite distinct from it, and Naturalists have called 

 this blacker substance by the name of Is'is. It may per- 

 haps be the work of a separate animal, associated, as in 

 these instances, with the Gorgonia. 



