156 LECTURE vm. 



Class ANTHOZOA. 

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

 margins. Stomach suspended by radiating mesogastric folds in an 

 abdominal cavity: no intestine. Polypary, 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, Actinodendron, JEumenides, 

 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 ZoANTHrojE. Genera, Zoanthus, Mammilifera. 

 b. With eight pinnate tentacles. Family Xenuds:. Genera, 

 Xenia, Anthelia. 



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

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

 tached calcareous spiculai. Genera, Alcyonium, Lobularia, Alcyo- 

 nidium, Ammothea, Nephthya, Sympodium. 



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

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

 supported by, and sometimes arranged more or less symmetrically 

 on a stem with a horny or calcareous axis. Family Pennatulid^. 

 Genera, Pennatula, Virgularia, Renilla, Verelillum, Pavonaria. 



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

 in calcareous tubes. Family Tubiporium. 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, 

 Fungia, Agaricia, Meandrina, Pavonia, Explanaria. b. With 

 more than twelve tentacles. Genera, Turbinolia, Lobophyllia, 

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

 Genera, Madrepora, Oculina, Astrcea. d. With the tentacles 

 obsolete. Genera, Millepora. 



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

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

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

 Genera, Gorgonia, Corallium, Isis, Melitcea. 



Class BRYOZOA. 

 Tentacles hollow, with ciliated margins. Alimentary canal with 

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

 horny or calcai'eous. 



