358 MANUAL OF NATURAL HISTORY. 



with a fleshy cortex ; polyps prominent, scat- 

 tered over the whole surface. 



5. Family. — Horny-Corals (Antipathic!^). Poly- 



pary fixed, ramose ; axis horny, solid, flexi- 

 ble ; cortex gelatinous, disappearing when 

 dried ; polyps prominent, scattered over the 

 entire surface. 



6. Family, — Sea- Fans (Gorgoniidse). Polypary 



fixed, branching, often reticulate ; axis horny, 

 solid, flexible ; cortex thick, firm, porous, 

 cretaceo-gelatinous, persistent when dried ; 

 polyps scattered over the whole surface. 



7. Family.— Arragonite-C orals (Briareidse). Poly- 



pary branched, formed of large, transparent, 

 rough, fusiform spicula, regularly placed side 

 by side along the stems, embedded in the cor- 

 tex, cortex covered with large conical tubercles. 



8. Family. — Glass -Rope Corals (Hyalonemidae). 



Axis composed of a congeries of siliceous fila- 

 ments, slightly twisted together in the form 

 of a rope, covered with a coriaceous tubercu- 

 lated cortex ; tubercles depressed, scattered. 



9. Family.— Incrusting-Corals(ClsiV'alsiru.dsd). Poly- 



pary in the form of a thin flattened mass, co- 

 vering marine objects ; polypi non-retractile, 

 with eight pectinate tentacles, prominent, 

 close together on the surface. 



10. Family. — Organ-Corals (Tubiporidse). Poly- 



pary composed of calcareous tubes arranged 

 in stages like the pipes of an organ ; polyps 

 terminal, in the mouths of the tubes. 



