156 LECTURE vm. 



Class ANTHOZOA. 

 Tentacles hollow, with thread-cells, and, in most, with pectinated 

 margins. Stomach suspended by radiating mesogastric folds in an 

 abdominal cavity : no intestine. Pohjpary, when present, usually 

 internal. 



A. Free and solitary, without polypary. a. Tentacles simple, rarely 

 branched or clavate, more than twelve, often in more than one row. 

 Family Actiniid.^. Genera, Actinia, Acti?iodendro7i, Eumenides, 

 Edvardsia. b. Tentacles clavate and aggregated in tufts on the 

 corners of the angular disc. Genus, Lucernaria. 



B. Fixed, compound, without polypary. a. With many simple ten- 

 tacles. Family Zoanthid.^. Genera, Zoantlius, ManuniUfera. 

 b. With eight pinnate tentacles. Family Xeniid.^. Genera, 

 Xenia, Ajithelia. 



C. Fixed, compound, polypes with eight pinnate tentacles, retractile 

 in cells of an amorphous fleshy substance, strengthened by de- 

 tached calcareous spiculce. Genera, Alcyonium, Lobidaria, Alcyo- 

 nidium, Ammot/tea, Nephthya, Sympodiiim. 



D. Free, compound, polypes with eight pinnate tentacles, retractile 

 in cells of a fleshy substance, strengthened by calcareous spiculce, 

 supported by, and sometimes arranged more or less symmetrically 

 on a stem with a horny or calcareous axis. Family Pennatulidm. 

 Genera, Penjiatula, Virffularia, Benilla, Vcretil/um, Pavonaria. 



E. Fixed, compound, polypes with eight pinnate tentacles, retractile 

 in calcareous tubes. Family Tubiporibje. Genera, Tubipora, 

 Catenipora. 



F. Fixed, compound, polypes retractile in calcareous cells on the sur- 

 face of a calcareous axis, which they cover with their common con- 

 necting tissue, a. With numerous and simple tentacles. Genera, 

 Fimgia, Agaricia, 3Ieandrina, Pavonia, Explanaria. b. With 

 more than twelve tentacles. Genera, Turbinolia, Lobophyllia^ 

 CaryophylUa. c. With not more than twelve pinnate tentacles. 

 Genera, 3Iadrepora, Oculina, Astrcea. d. With the tentacles 

 obsolete. Genera, 3IiUepora. 



G. Fixed, compound polypes, with eight pinnate tentacles, retractile 

 in cells of a fleshy substance, strengthened by calcareous spiculce, 

 and supported on a branched, calcareous, firm or flexible axis. 

 Genera, Gorgonia, Corallium, Isis, Melitcea, 



Class BEYOZOA. 

 Tentacles hollow, with ciliated margins. Alimentary canal with 

 stomach, intestine, and anus. Polypary , when present, external, 

 horny or calcareous. 



