XVlll 



painter's brush, or take the form of an umbrella ; some 

 resemble an open fan ; in short, some are simple, 

 some are branched, some articulated, some com- 

 pressed, some flat, and some cylindrical. 



The Corticiferous Polypidoms display an equal 

 variety : there are Spongiae that spread in thin patches 

 on the rocks and marine plants ; others form them- 

 selves in globular masses, or are hollowed in the 

 form of tunnels ; many rise in tubes like the pipes of 

 an organ, and some divide in the form of thick leaves. 

 What diversity of forms between the Gorgonias with 

 a simple unbranched stem, and others whose ana- 

 stomosised branches resemble fishing-nets, from their 

 net-work and extent ! The Flabellated Amlyomena 

 exhibits meshes so regularly and elegantly designed, 

 that they strike us by their resemblance to lace. 



The Isidias have an alternately stony and cartila- 

 ginous stem, bearing some resemblance to the ver- 

 tebrae of animals more perfect in their organization ; 

 others in appearance may be compared to shrubs 

 despoiled of their leaves, but covered with flowers 

 whose whiteness is rendered more conspicuous by 

 the deep and brilliant red of the branches. 



To conclude : in the Carnoid Polypidoms differ- 

 ences almost as numerous exist, but much less known 

 than those described in the preceding Orders, 



