NORTH ZOOL. GAL.] NATURAL HISTORY. 
141 
simple and separate from each other, as the Fungia, 
(Case 2,) and if these are understood, the structure of 
the other kinds will readily be made out, for they are all 
formed in the same manner, although they are much 
modified in their outward form by being crowded to¬ 
gether into a hemispherical mass like the Brain-stone* 
(Case 10,) in the form of a tree-like Coral, (Case 15,) or 
of an expanded frondose mass, like the Explanaria. All 
these variations result from the manner in which the 
animal emits from the whole surface, or from a particular 
part of the sides of its body, the bud by which the new 
individuals of the general mass or society are produced. 
In the greater part of these animals, the stomach is 
furnished with numerous folds, leaving many plates in the 
cells of the coral, and the mouth has generally equally 
numerous tentacles, as in the Sea Anemonies, or Actinice . 
In some, as the Fangia , Tin blnolia^nd Cyathina ,(Case2*) 
the animals are simple and solitary, and not spontaneously 
divided, so that the coral only offers a single cell. In 
others, where the animals live in societies, the mouth 
often contracts on the side and separates of its own 
accord gradually into two or more mouths; it then pro¬ 
duces as many separate cells, which are separated or 
forked where the contraction took place. In some 
of these, as the LobGphyllia , &c.* (Case 3,) the bodies 
of the different animals of the same mass, and the cells 
of the coral remain separate from each other. In a 
few, as Anthopliyllmn , (Case 7,) at certain intervals of 
its growth, the animals throw out an expansion which 
deposits a shelly plate that unites the different cells 
formed by each of the bodies into a common mass, though 
the cells themselves are distant from each other. But 
in very many, the bodies of the different animals of 
the same group, as they are produced, are united to¬ 
gether side by side, forming a coral with all the cells 
united together into a globular, branched or expand¬ 
ed foliaceous mass. These forms depend on the man¬ 
ner in which the reproduction of the different individuals 
of the masses takes place, wdiether by the contraction 
and spontaneous division of the mouth, when the cells 
are deep and form a rounded mass, or by the develope- 
ment of buds from the sides of the parents, when the 
animal forms an expanded frond* as in Pavonia ) &c. 
