TRIBE II I. MADREPORACEA. 511 



GENUS I. ALVEOPORA. BLAINVILLE. 



Alveoporina glomeratce aut furcato-ramosce ; corallis spongiosis ; cellis 

 contiguis parietibus tenuissimis et aperte cribratis ; septis transversis 

 remotis. 



Glomerate or furcato-ramose ; coralla spongy ; cells contiguous, with 

 the sides very thin, and thickly pierced with holes ; transverse septa 

 remote. 



The Alveopone are either glomerate or ramose in their mode of 

 growth, and attain a large size. The coralla are very light, and open 

 cellular; and the parietes of the polygonal cells, as exhibited by a 

 vertical section, look much like lace-work. The lamellaB of the cells 

 are represented by a few slender points or spicula. 



The animals of the Alveopone were first accurately figured by 

 Savigny, who found them prominent when expanded, with a circle of 

 twelve tentacles around the mouth; though near the Porites in this 

 respect, as well as in the porous corallum, yet the deeper cell, trace- 

 able through the corallum, and its structure within, affiliates them 

 more strongly to the species with which they are here associated. 

 They are intermediate in character between the Manoporse on the one 

 side, and the Favositinse on the other. They are confined to the coral- 

 reef seas, and have been found only in the Pacific and Indian Oceans. 



The genus Alveopora was instituted by Blainville, for some of the 

 Porites of Lamarck, and certain Pacific corals obtained by Quoy and 

 Gaymard, in their celebrated voyage of discovery. The name is de- 

 rived from the Latin alveum, a bee-hive. 



Arrangement of the Species. 



I. Glomerate. 



1. A. retepora. *3. A. spongiosa. 



*2. A. dedalea. 



II. Branched. 



4. A. rubra. 5. A. fenestrata. 



