320 THE OCEAN. 
ference, of a dull brown hue, the body and legs 
entirely covered with stiff, curved bristles. It covers 
itself with decaying vegetable rubbish, mud, sand, 
&c., and thus lies in ambush for its passing prey. 
Thus masked, it maintains its assumed character 
by the most sluggish movements, as if the little 
heap were slightly moved by the tide; but, when 
taken into the hand, or otherwise alarmed, it can 
be sufficiently active. The spines upon its body 
to retain the rubbish, the short but strong claws 
easily concealed, the eyes placed at the end of long 
footstalks, curving upwards and thus raised above 
the mass, show beautiful adaptations of its structure 
to its economy. 
Another crab of the reef (Calappa tuberculata), 
makes use of another artifice for concealment. It 
is heart-shaped, with the margin of its shell pro- 
jecting broadly. When alarmed, it draws its feet 
under the margin, and folds them close to its side, 
claps its broad flat claws upon its head, and lies 
motionless, in which state it may be handled with- 
out manifesting any sign of life. <A sailor seeing 
one of these little crabs on the shore, picked it up, 
and after admiring it awhile, put it into his pocket 
as a “curious stone ;” he was presently astonished by 
the efforts of his prize to escape from durance vile. 
On the barrier reefs are found elegant animal- 
flowers (Diazona), expanding their numerous tenta- 
cles of pink and white, which form a wide circular 
disk, at the summit of a round fleshy stem. If 
touched, or otherwise alarmed, they rapidly fold in- 
wards their beautiful tentacles, and sink to the rock, 
