XV1U 
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 Andyomena 
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, 
