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 (Cahppa tuberculoid), 

 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, 



