144 THE MARINE BOTANIST. 



in suitable situations, tliey continue enlarging* in 

 concentric circles, each marked with a pale zone, 

 until they ultimately cover a space of several 

 inches in diameter. The resemblance, in this 

 condition, which the crust has to some crustaceous 

 fungi, more especially to Polyporus versicolor, is 

 remarkably exact; and neither is it less variable 

 than the fungus in its growth, the variations 

 depending on the nature of the site from which 

 it grows. If this is smooth and even, the foliaceous 

 coralline is entii-ely adnate and also even; but if 

 the surface of the site is uneven or knotted, the 

 coralline assumes the same character. If it grows 

 from the edge of a rock, or on the frond of a 

 narrow sea-weed, or from a branch of the perfect 

 coralline, the basal laminse spread beyond in over- 

 lapping imbrications of considerable neatness and 

 beauty. They are semicircular, wavy, either smooth 

 or studded with scattered granules, and these 

 granules (ceramidia) may be either solid or per- 

 forated on the top. Such states of the coralline 

 have been described as Ifillepora lichenoides ; 



