171 



CHAPTER VII. 



ZOANTHARIA. 



" T saw the living pile ascend 

 The mausoleum of its architects, 

 Still dying upwards as their labour closed : 

 Slime the material, but the slime was turned 

 To adamant by their petrific touch." 



Montgomery's Pelican Island. 



The creatures which constitute the class Zoantharia are quite great 

 personages. Some of them are eighteen or twenty inches long ; at 

 the same time, others scarcely exceed the eighth part of an inch in 

 length. They live in all seas, and seem to have existed through many 

 ages of the earth's history ; they appear at an early geological period, 

 and they have performed an important part in its formation. 



The name of Zoantharia was first given to the class by Dr. J. E. 

 Gray ; but here we give it a somewhat wider signification, embracing 

 under it the madrepores and starred stones of Lesueur, who was 

 reminded of a field enamelled with small flowers when he saw the 

 little polyps of Pontes astroides in full blow. " But it is only," says 

 Johnston, " when they lie with their upper disc expanded, and their 

 tentacula displayed, that they solicit comparison with the hosts of 

 Flora ; for, when contracted, the polyps of the madrepores conceal 

 themselves in their calcareous cups, and the actinia hide their beauty, 

 assuming the shape of an obtuse cone or hemisphere of a fleshy con- 

 sistence, or elongating themselves into a sort of flabby cylinder that 

 indicates a state of relaxation and indolent repose." 



These zoantharia are flesh-eaters, and consume quantities truly 

 prodigious of animals such as crustaceans, worms, and small fishes. 

 They are all marine, nearly all attached to the same spot for life, and 

 they live in colonies. Some few are isolated and live by themselves, 

 either free or attached to the soil. They differ altogether from the 

 animals belonging to the Alcyoiiaria by the number and peculiar fomi 

 of their tentacula. These appendages in the Zoafit/iaria never present 

 the bipin7iate arrangement which is observable in the Alcyonaria. 



