1 86 



THE OCEAN WORLD. 



two feet in height. The polyps are provided with a great number of 

 tentacula, in the centre of which the mouth is placed ; they are 

 deeply buried in the cells. Peyssonnel, who had seen the polyps 

 forming one of such a colony, says : " I may observe that the ex- 

 tremities or summits of the branching madrepore, the species in 

 question, which in the Provencal we call ' sea-fennel,' is soft and 

 tender, filled with a glutinous and transparent mucous substance, 

 similar to that which the snail leaves on its path. These extremities 



Fig 6r. — Dendrophyllia ramea (De Blainville). 

 Natural size, with polypi. 



Fig. 70. — A part magnified. 



are of a fine yellow colour, five or six lines in diameter ; soft, and 

 more than a finger's breadth in length. I have seen the animal 

 nestling in them ; it seemed to be a species of cuttle-fish or sea-nettle. 

 The body of this sea-nettle must have filled the centre ; the head 

 being in the middle, surrounded by many feet or claw^s, like those of 

 the cuttle-fish. The flesh of this animal is very delicate, and is easily 

 reduced to the form of a paste, melting almost under the touch." 



The madrepores abound in all intertropical seas, taking a con- 

 siderable part in the formation of the reefs which form the coral and 

 madreporic islands so conspicuous in the three oceans. The tree- 

 like Dendrophyllia {D. ramea, Figs. 68, 69, and 70) have cells of con- 



