32 



CCELEXTERATA. 



Zoanthidce. 

 Zoanthus. 

 Palythoa. 



Cerianthidts. 

 Cerianthus. 



Minyadid(B. 

 Minyas. 

 Nautactis. 



ActiniidcB. 

 Thalassianthus. 

 Adanisia. 

 Tealia. 

 Bolocera. 

 Bunodes = Cereus. 

 Actinoloba. 

 Sagartia. 

 Capnea. 

 Corynactis. 

 Aiptasia. 



Anthea = Anemonia. 

 Actinia. 



llyantliidcs. 

 Edwardsia. 

 Ilyantlms. 

 Peacbia. 

 Halcampa. 



Arachnactis. 



Order II. SCLEEOBASICA. 

 ANTIPATHARIA. 



Corallum external, not calcareous. Tenl ''es six, simple. 

 Polypes united, included within the corallum. 



There is a rough, stem- like, branched, horny axis, or coenosare, 

 covered by a very friable ccenenchyma, which generally becomes 

 detached in drying. 



Few species of this order are known, and they are mostly from 

 the Mediterranean. One of the species of Antipathes has a tapering 

 coenosarc nine feet long, with the diameter at the base - 3 of an inch. 



Antipathida. Arachnopatb.es. Gerardiida. 



Antipathes. Leiopathes. Gerardia. 



Order III. SCLEEODEEMATA. (Stone- corals.) 

 MADREPORARIA. LITHOCORALLIA. CORALLIGENA. 



Corallum internal, calcareous. Tentacles more than six. 

 Polypes generally united. 



The corallum-tissue is firm and compact in the Eporosa, porous 

 and granular, or even spongy, in the Perforata. The Eugosa 

 (Tetracoralla) are only known from the remains of extinct forms ; 

 in these there are four septa, in all the others six, at least in the 

 young state. 



The coral-reefs of warm seas are built up by the members of 

 this order, mostly Astrjeidae. The largest of these, the Great 

 Barrier Eeef, is 1200 miles long, and 20 to 100 broad. The coral 



