232 CffiLENTEBATA. 



The body is seldom quite soft, or with a leathery framework ; as a 

 rule it has a calcareous stony polyparium with radial striations. 

 Separated sexes are the rule, but hermaphrodite polyps (Actinia) 

 are not seldom, to be met with. The polyps very generally retain 

 their embryos for a long time, so that they are born eight or twelve 

 rayed, with rudimentary tentacles. Many give rise to coral reefs 

 and islands (tigs. 175 179). 



1. ANTIPATHARIA. Mostly with only six tentacles, and horny skeletal axis. 

 Fam. Antipathidae. Polyp stocks with soft non-calcareous body, but with 



simple or branched axial skeleton. Only six tentacles surround the mouth, /'.;/., 

 AnfijHitJtrx Pall. 



2. ACTINIARIA, with no hard structure. 



Fam. Actinidce. with soft body : sometimes single animals with several 

 alternating circles of tentacles, Act i it in L. ; sometimes connected in stolons 

 and aggregated to form stocks, Xntnttkux Cuv. The former are able, by means of 

 their contractile foot, to leave their place of attachment and to move freely. 

 Many reach a relatively considerable size, and possess beautiful colours. Under 

 the name of sea anemones they are the ornaments of salt water aquaria. 

 Actinia mesembryanthemwm L. The skin sometimes secretes a glutinous mass 

 filled with nematocysts or a kind of membrane, Crrim/tltim Delle C'h. 



3. MADEEPORARIA with continuous hard calcareous skeleton. 



(rt) A.pOT08Oi. 



Fam. Turbin.olid.ae. Mostly single polyps with compact calcareous frame- 

 work, imperforate thecae, and well developed septa, the spaces between which 

 are open to the bottom. Turljinolid Lani., Flnhcllnm Less., Caryopliyllia 

 Lam., C. ci/atlnix Lam., Blastotroehus Ed. H. 



Fam. Oculinidae. Polyp stocks with hard usually branched polyparium, with 

 coenenchyma rich in calcareous matter, and but few septa in the cup of the 

 individual. Ocullntt rirginc/t Less.. Indian Ocean. AinpJiiJielia ncttlattt. L., 

 white corals of the Mediterranean. 



Fam. Astrae'idae, Star corals, Mostly massive polyp stocks with fused thecte, 

 and without coenenchyma. The septa have sometimes cutting edges, sometimes 

 toothed edges. The interseptal spaces are rilled with horizontal partition walls. 

 -Euxiiiiliu Edw. The single animals are produced by fission and remain 

 connected only at their bases. They produce a cespitous polyparium. the 

 septal edges of the cup being cutting, (j-altu'cti Oken. The single cups arise 

 by gemmation, are free at the upper edge ; the septa have cutting edges. Axtrerti 

 Lam., single cups fused throughout the entire wall. The septal edges of the 

 cup are jagged. Ma-ttitd rintt Lam., the neighbouring cups fused to form long 

 valleys. M. Crasxa- Edw. H. 



Fam. Fungidae. Mushroom corals. Usually with large flat single cups, some- 

 times polyp stocks ; without thecas, with numerous strongly developed septa, 

 toothed and connected by synapticulaa. Fuitghi dixctts Dana., Halowitrti 

 liana.. Lophiwrix Edw. H. 



(//) Pcrfornttt. 



Fam. Madreporidae, Madrepores. Polyps and polyp stocks with porous 

 coeneuchyma and perforated thecse. Gastric cavity open at the bottom and 

 communieating with the central canal in the axis of the branched polyparium. 



