504 STONY CORALS; CARYOPHYLLIA, DENDROPHYLLIA. 



chambers, and, like them, radiating from the centre towards the 

 circumference of the cell. These radiating lamellae are, in fact, 

 characteristic of all the Coral structures formed by the group of 

 Helianthoid Polypes ; being present, more or less evidently, in 

 every one known to be the work of these animals, and not 

 occurring in any, of which the animal is known to resemble either 

 of the other groups. The cells are not by any means constantly 

 circular; but still the laminated plates project inwards from their 

 circumference, so as to occupy a corresponding position. The 

 Madrepores and their allies have thence been designated lamelli- 

 form corals ; a term which is very expressive of their character, 

 and has the advantage of relating to the structure of the animals 

 which produce them. 



1072. Some species of Caryophyllia build up their cells in a 

 cylindrical form, to a considerable height (Fig. 618). As the 

 upper edge is extended by the gra- 

 dual consolidation of the soft structure, 

 which is the continuation of it, the 

 lower part is strengthened by new de- 

 posits, which are added to the bottom of 

 the cell ; so that a stony column is thus 

 formed, which may almost be described 

 as solid through nearly its whole extent. 

 It is not uncommon to meet with several 

 of these, clustered in one mass ; and 

 thus we can understand the production 

 FIG. 6i8.-CAHvoPH.LUA. of thoge . arborescent (tree-like) forms, 



to which the name Dendrophyllia has been given. In these, 

 the stem sends out branches, instead of remaining simply 

 columnar ; and these branches again subdivide ; in all instances, 

 however, the cells terminate the branches, which increase in 

 length by the progressive*fconsolidation of their basis, just as in 

 the solitary species. The whole structure is covered with a 

 gelatinous flesh of some consistence, which seems to be continuous 

 with the outer membrane of the Polypes inhabiting the cells. 

 This flesh appears to have the same functions with the pith of 

 the Sertularian Polypes. It seems, in fact, to constitute the 



