CCELENTERATA. 
251 
long-lived compared with the Hydrozoa, living for several 
years. One kept in aquaria in England is now more than 
sixty years old. 
1. Soft-bodied Polyps.—The best-known representa¬ 
tive of this group is the Actinia , or Sea-anemone. It 
leads a single life, and is capable of a slow locomotion. 
Muscular fibres run around the body, and others cross 
these at right angles. The tentacles, which often number 
over two hundred, and the partitions, which are in reality 
double, are in multiples of six. At night, or when alarmed, 
the tentacles are drawn in, and the aperture firmly closed, 
so that the animal looks like a rounded lump of fleshy 
substance plastered on the rock. It feeds on Crabs and 
Mollusks. It abounds on every shore, especially of trop¬ 
ical seas. The size varies from one eighth of an inch to a 
foot in diameter. 
2. Coral Polyps.—The majority of Anthozoa secrete 
a calcareous or horny framework called “ coral.” With 
few exceptions, they are fixed 
and composite, living in colonies 
formed by a continuous process 
of budding. Their structures take 
a variety of shapes: often dome¬ 
like, but often imitating shrub¬ 
bery and clusters of leaves. The 
members of a coral community 
are organically connected; each 
feeds himself, yet is not indepen¬ 
dent of the rest. We can speak 
of the individual Corals, a , 5, c , 
but we must write them down 
abc. The compound mass is “like Fig. 200 .— organ-pipe corauruw. 
,. . . . . . pora mu8ica). Indian Ocean. 
a living sheet of animal matter, 
fed and nourished by numerous mouths and as many 
stomachs.” Life and death go on together, the old 
