COELENTERATA. 
241 
Cxiass I].—Anthozoa. 
These marine animals, which by their gay tentacles con- 
vert the bed of the ocean into a flower-garden, or by their 
secretions build up coral-islands, 
have a body like a round gelat- 
One end, the base, 
is usually attached; the other 
has the mouth in the centre, 
surrounded by numerous hol- 
low tentacles, which are coy- 
ered with nettling lasso - cells. 
This upper edge is turned in 
inous bag. 
so as to form a sac within a 
sac, like the neck of a bottle 
turned outside in. The inner 
Fig. 193.—Horizontal Section of Ac- 
tinia through the stomach, show- 
ing septa and compartments. 
one, which is the digestive cavity, does not reach the bot- 
tom, but opens into the general body-cavity. 
The space 
between these two concentric tubes is divided by a series 
of vertical partitions, some of which extend from the 
body-wall to the digestive sac, but others fall short of it 
Fig. 194, -- Actinia expanded, seen from above, 
showing mouth. 
16 
Instead, therefore, of 
tubes of 
the Acaleph, there are 
-the radiating 
radiating spaces. No 
members of this class 
are microscopic. Allare 
long - lived cempared 
with the Hydrozoa, liv- 
ing for several years. 
1. Soft-bodied Pol- 
yps.—The best-known 
representative of this 
group is the Actinza, or 
Sea-anemone. Itleads a 
