CORALS 



151 



Some of them may easily be fancied to have been selected for 

 halcyons' nests, as the name suggests the sea-fans, for example 



ORDER ALCYONACEA 



GENUS Alcyonium 



A* palmatum. This coral community is found sometimes at low- 

 water mark, but usually in deeper water, attached to shells and stones. 

 It is commonly known as dead-men's-fingers, an unpleasant name 

 given it by fishermen because of a fancied resemblance to a human 

 hand with only the stumps of the fingers. The substance of the coral 

 is semi-cartilaginous, with scattered spicules of lime which give it 

 stability. When the polyps are fully extended the colony is rather at- 

 tractive in appearance, but not so when contracted. It is found in 

 abundance on the New England coast. An immense Alcyonium, Para- 

 gorgia arborea, grows on the fishing-banks off Newfoundland, and is 

 sometimes brought up on the fishing-lines. It is tree-like in form, and 

 measures six feet or more in length. 



GENUS Tubipora 



The organ-pipe coral. This genus, which is deep red in color 

 and very fragile, consists of many tubes slightly separated from 



Tubipora, organ-pipe coral, natural size. 



