32 8 COELENTERATA ANTHOZOA chap. 



over the rocks or seaweeds, others habitually burrow in the 

 sand {Udwardsia, Cerianthus), and one family (the Minyadidae) 

 are supported by a gas bladder, and float at the surface 

 of the sea. The Sea-pens, too, although usually partly buried 

 in the sand or mud, are capable of shifting their position 

 by alternate distension and contraction of the stalk.^ The 

 Anthozoa are exclusively marine. With the exception of a few 

 Sea-anemones that are found in brackish or almost fresh water in 

 river estuaries, they only occur in salt sea water. The presence 

 of a considerable admixture of fresh water, such as we find at 

 the mouths of rivers, seems to interfere very materially with the 

 development and growth of all the reef-forming Corals, as will 

 be noticed again in the chapter on coral reefs. A few genera 

 descend into the greatest depths of the ocean, but the home of 

 the Anthozoa is pre-eminently the shallow seas, and they are 

 usually found in great abundance in depths of 0-40 fathoms 

 from the shores of the Arctic and Antarctic lands to the 

 equatorial belt. 



The only Anthozoa of any commercial importance are the 

 Precious Corals belonging to the Alcyonarian family Coralliidae. 

 The hard pink axis of these corals has been used extensively 

 from remote times in the manufacture of jewellery and orna- 

 ments. Until quite recently the only considerable and 

 systematic fishery for the Precious Corals was carried on in the 

 Mediterranean Sea, and this practically supplied the markets 

 of the world. In more recent times, however, an important 

 industry in corals has been developed in Japan. In 1901 the 

 value of the coral obtained on the coasts of Japan was over 

 £50,000, the greater part of which was exported to Italy, a 

 smaller part to China, and a fraction only retained for home 

 consumption. The history of the coral fishery in Japan is of 

 considerable interest. Coral was occasionally taken off the coast 

 of Tsukinada in early times. But in the time of the Daimyos 

 the collection and sale of coral was prohibited, for fear, it is said, 

 that the Daimyo of Tosa might be compelled to present such 

 precious treasure to the Shogun. After the Meiji reform, how- 

 ever (1868), the industry revived, new grounds were discovered, 

 improved methods employed, and a large export trade developed. 



There is evidence, however, in the art of Japan, of another 



' Cf. Darwin, Voyage of the Beagle, chap. v. 



