MADREPOKARIA I OCULINID^E. 



527 



Astrcea pallida, Dana. 

 Portion of a large dome, alive 



ASTR,EID,E, OR SxAR-CoRAL FAMILY. This Family 

 has the coralla with concave Fig. 527 



radiate cells ; septa in aggre- 

 gate species not continuous 

 from one centre to another, but 

 generally interrupted half-way. 

 The prevailing forms are hemi- 

 spherical or dome-shaped, and 

 some of the large domes of the 

 Astraeas are even twenty feet in 

 diameter. The Genus Astrcea 

 of Lamarck is the principal one. 

 The polyps are often an inch 

 in diameter. 



The Genus Astrangia is rep- 

 resented on the coast of North and South Carolina by A. 

 astrceiformis, M.-Edw. & Haime ; and in Long Island 

 Sound by A. Dance, Ag. The latter is found incru sting 

 rocks from just below low-water mark to ten fathoms. It 

 thrives well in the aquarium, eating mollusks with avidity. 



OCULINID.E. This Family contains the Genus Ocu- 

 lina, which has the corallum, while young, spreading lat- 

 erally by basal budding, and forming an incrusting base 

 from which branches arise in tufts or arborescent forms ; 

 cells rather deep, and edges of the septa entire. Fig. 525. 



O.arbuscula, Ag., occurs off Charleston, South Carolina. 



The Sub-Order of Fungacea contains those m which 

 the polyps are simple, or compound by marginal or disk 

 budding ; tentacles nu- Fig. 52 s. 



merous in multiples of 

 six, usually short, lobe- 

 like, and scattered on 

 the actinal surface ; and 

 the coral broad and low, Fun z ia - Some s P ecies a foot in diameter 

 and not transversely septate. There are four families, 

 Cycloclitidae, Lophoseridae, Fungidse, and Merulinidae. 



