52 



CORALS AND CORAL LS LANDS. 



branches, which, when alive, have literally the aspect of sprigs 

 of flowers in the vase. 



In certain kinds, closely related to Madreporae, the calicles 

 are reduced to points, or spiniform or angular prominences, or 

 fail altogether, and there are sometimes rounded prominences 

 between the cells ; these degraded Madrepores belong to the 

 genus Montipora (Manopora of the Author's Report). 



The genus Dendrophyllia is also referred to the Madrepore 

 tribe. The budding, as already explained, is of the same 

 kind as in the Madrepores. But the tentacles exceed twelve. 

 One of the polyps of D. nigresce?is D., 

 enlarged, is shown in the accompany- 

 ing figure. This Pacific species grows 

 to a height of at le.ist three feet, and 

 is peculiar in having a very dark 

 blackish green or almost black colour, 

 while the polyps have the tentacles 

 nearly colourless, and the disk has a 

 circle of emerald green around the 

 mouth. DeiidrophyUia arborea is the 

 name of a common species of his 

 genus found in deep water in the 

 Mediterranean ; it is equally large 

 with the preceding, and somewhat 

 similar in its mode of branching, but a little stouter. It has 

 also been found in the Atlantic about the Azores. Another 

 common Mediterranean spegies is the D. cor?ngera. It is 

 sparingly branched, and has very long and stout corallets, 

 sometimes as long and large as the finger. 



The genus Gemmipora contains porous corals, of foliaceous, 

 bowl-like, and massive forms, covered by prominent cylindri- 

 cal, porous calicles, and having many short tentacles to the 

 polyps, usually in a single circle. 



Here belongs also the large Porites family (Poritidse), the 

 corals of which are very porous, and sometimes almost spongy, 

 and whose polyp-cells are exceedingly shallow, and usually 

 only imperfectly radiated. 



POLYP OF DENDROPHYLLIA 

 NIGRESCENS. 



