of Keratophyta. 6^ 



it dies, the Animal of the Milkpora Coral Kind frequently 

 incrufts its dead Branches with a white coral Matter, fo that 

 many Perfons have been deceived by not examining it care- 

 fully, and have taken it for a calcarious, inftead of a flony, 

 Incruftation. But, bciides the Difference of the Materials of 

 which thefe Coverings are compofed, the Irregularity of the 

 Coral is eafily to be diftinguiOied, from the great Exadnefs 

 of the natural Incruftation. 



Another Obfervation naturally follows this ; and that is, 

 we never find upon one and the fame Species of Keratophy- 

 to7i, two different kinds of calcarious Incruftations. Not- 

 withftanding I have feen three different Species of KeratO' 

 phyta adhering to one Piece of Rock-coral ; and in the 

 fame Piece, Part of a dead Keratophyton incrufted with the 

 Coral. 



The Particles of this cortical Cruft, which are of a pecu- 

 liar Figure in each Species, are often deeply impreffed into 

 the laft Row of Tubes, which are now become woody or 

 horny, from having their calcarious Parts mixed with the 

 glutinous Parts of the Animal, and are the prefent Surface 

 of the inner Part. 



No Bark, Membrane, or other outfide Covering, are ever 

 found on this Genus of marine Produdlions, except this cel- 

 lular calcarious Coat, which Oievvs it to be its natural one. 



Whoever has carefully examined the upright and crofs 

 Sedions of Trees and Shrubs, or even the Stems of Sea- 

 plants, wiU find, that the longitudinal Veffels of the woody 

 Parts are always conneded together by lateral Fibres, or 

 have lateral Tubes. But on the niceft Enquiry we could 

 make with the Microfcope, we could never difcover any of 

 thefe connecting Fibres, or Tubes, proceeding trom the Pith 



K to 



