170 
THE OCEAN WORLD. 
sents certain yellow or grass-like points, which gradually expand and 
display themselves in their native transparent and animated coralline. 
Each of these polypes have eight dentate petals, in the centre of which 
is the mouth ; the body of the polype is tubular, varying externally in 
length, traversed internally throughout its entire mass by a tissue 
studded with reddish spiculfe, and furrowed with small reed -like 
ribbons, common to all the individuals of the association. 
Among the Tulnporidiv may be noted Tubipora rnmica (Linnaeus), 
from the Indian Ocean, characterised by its stony tubes, simple, nume- 
rous, straight or flexiblo, parallel, and slightly radiating, of a fine 
purple, and united together at intervals by transverse bands, so as to 
resemble the pipes of an organ. The polype is a brilliant grass green, 
according to Peron ; the tentacula furnished on each side with two or 
three rows of granulous fleshy papillae, to the number of sixty to eighty 
( Lesson). 
The Gorgonia is studded with calcareous or siliceous spicuhe which 
form a crust in drying. This crust is friable, and frequently preserves 
the colours more or less brilliant which characterise it. Their cells 
are sometimes hollowed out of the plain surface ; sometimes they occur 
in the projecting mammals ; these are smooth, rough, or scaly — some- 
times pendent the one from the other. 
The polypiers attach themselves to solid bodies, sometimes even to each 
other, grafting themselves or interlacing each other in all directions. 
In colour they are whitish, pure white, yellow, and apple-green ; their 
shades, passing from olive-brown to deep blue, from vermilion to violet, 
and from pale yellow to pearly-grey. Each tube or cell contains an indi- 
vidual. The cells are more or less deep, according to the species. The 
polypes are composed generally of a hidden portion more or less tubular, 
and of a star-like portion more or less displayed. This latter portion 
presents from eight to twelve soft and granulous wattles, susceptible of 
expansion, like the petals of a flower. When these appendages are 
displayed, they often attain twice the height of the body ; in this state 
they are nearly transparent, except towards the extremity. They 
extend or compress these wattles, dilate or contract the mouth ac- 
cording to their wants ; but their digestive tube is firmly soldered to 
the cell, while the axis which supports the colls is motionless. What 
a singular combination is hero presented ! Trees, one-half of which are 
animated, growing at the bottom of the sea ; animalcules, one-half el 
