284 ZOOPHYTES. 



of proper limits to the disks of the animals. The surface is usually 

 covered with stars, and a central pore or puncture (oririme*), mark- 

 ing the position of the mouth, is all that exists of a cell. In some 

 species there is an excavation, like the cell of an Astrsea; but still they 

 have the central pore, in connexion with the characteristic of the 

 Fungidae, the continuity of the lamellae from centre to centre, instead 

 of their interruption along the middle of the septum. The peculiar 

 nature of these cells is explained in the remarks upon the genera 

 Agaricia and Psammocora. 



The animals of these corals were first figured by Forskal, who exa- 

 mined a Fungia, at the Red Sea, and has given an excellent repre- 

 sentation of it. The tinted tentacles scattered over the surface, give a 

 rich effect to the large umber disks, sometimes a foot or even eighteen 

 inches in diameter. In some species the tentacles are nearly obsolete, 

 and very generally, they appear only as inflations of the exterior mem- 

 brane, over a lamella at its origin. They are seldom if ever suffi- 

 ciently long to aid the animal in taking its food, and appear to be 

 used simply for the expulsion of the included water, on contraction, 

 and the aeration of the nutrient fluids, a function in which every part 

 of the body, more or less, shares. On contraction they disappear by 

 simple shrinkage, without being covered, as in the Astreeidse. 



The generic divisions of this group, depend on the mode of growth 

 and budding, and may be distinguished as follows : 



Arrangement of the genera of Fungida. 



I. Free not budding; a central oririme above. 



\. FrNGiA. Corallum lamello-radiate above, tuberculato-radiate below. 



2. CYCLOLITES. Corallum lamello-radiate above, concentric lines of growth below. 



II. Free ezplanato-gemmate. 



3. HEHPETOLITHUS. A continuous medial line of large polyps, with others smaller, 

 scattered either side ; a distinct circle of tentacles to each polyp-mouth. Corallum with 

 a long medial trench (compound oririme); surface consisting of short denticulate lamellae 

 scarcely at all radiate, half an inch to an inch long, none extending from the centre to 

 the circumference. 



4. HALOMITRA. Polyps all scattered ; a distinct circle of tentacles to each polyp- 

 mouth (?). Corallum without a medial trench ; lamellae nearly as in the preceding, but 

 more radiate and coarsely toothed. 



5. POLYPHYLIIA. Polyps all scattered, or an imperfect medial series ; a single ten- 

 tacle to each lamella, and not a separate circle to each polyp-mouth. Corallum without 



* From the Latin os, mouth, and rima, a cleft or fissure. 



