42 SEA-SHORE LIFE 
Sea anemones are found in all oceans, but the stony corals are 
practically confined to tropical and sub-tropical regions and will 

Fig. 17, Stony Skeleton of Star-Coral. 
Long Island Sound. 
not usually live in water which 
is colder than 66° F. In the trop- 
ical Atlantic and Pacific thousands 
of coral islands called atolls have 
been gradually built up by the con- 
stant growth of coral polyps, and 
every grain of sand on the Baha- 
mas, Bermudas, or Florida Keys 
was once part of the skeleton of a 
coral polyp or belonged to some 
animal or plant which lived among 
the coral reefs. 
The Star-Coral, (Astrangia 
dane, Figs. 16, 17). This stony 
coral extends farther into the tem- 
perate zone than any other species, being found from the Carolinas 
to Cape Cod. 
forms encrusting masses of 
star-like cups upon stones, dead 
shells, ete. 
The coral polyps are glassy 
white, and translucent, and 
have each from eighteen to 
twenty-four long, tapering ten- 
tacles which end in a white 
knob and are speckled over 
with white warts. These are 
the stinging organs which en- 
able the coral to capture its 
prey of small marine animals. 
When fully expanded the pol- 
yps are about one-eighth of an 
inch wide and_ three-eighths 
high, but when disturbed they 
suddenly contract so as to become practically invisible. 
It is abundant in Long Island Sound where it 

Fig. 18; FLESHY CORAL. 
Woods Holl, Mass. 
The colony 
starts with a single polyp but soon others bud out from its base, 
