SYNOPSIS. 

 1 1 1 1 1 Cells on ringed footstalks. 



Polypidoms confervoid; cells campanulate ; statu ^ 



jointed, cells rising from thickened parts of > Laomedea . 

 the stem ) 



Polypidoms confervoid ; cells campanulate. contin- } ~ 



noHs with the stem, irregular j Campanulas 



* * * Polypidoms internal. 

 t Horny, rooted. 

 Arborescent, fleshy, warty, with star-shaped de- ) r 



pressions, rooted \ ^orgonIa . 



t t Bony, free. 

 Polypidom linear, feathered at one end .... Pennatula . 

 Polypidom linear, with curved lines on either side. Virgularia . 



* * * * Polypidoms external, calcareous. 

 Columnar or conical, upper surface lamellated . . Caryofhyllia 



Arborescent, or foliaceous, stout ; cells immersed, ) „ 



. , ... -j i ? Retepora 



quincuncial, on the upper side only . . . $ 



Arborescent, or foliaceous, cells immersed, quin- ) v 



cunical, oval ; cells on all sides $ i^schara . 



Arborescent, jointed, cylindrical, cells immersed, ( p 



qnincuncial, rhomboidal ; cells on all sides . . \ arcimia. 



Arborescent, cells oval, distinct and irregularly ) ,-, 



, , ° J > Cellepora 

 heaped $ 



Arborescent, confervoid, jointed ; cells tubular, ) „ 



apertures round, terminal. ....... \ RISIA> • 



Arborescent, confervoid, jointed ; cells oblong, \ p 



apertures opening on one plane £ ellularia 



Arborescent, confervoid, jointed ; cells sub-cylin- 1 



drical in pairs, apertures lateral and subter- > Notamia. 



minal ) 



Poljpidoms creeping, cells erect, spathulate, aper- ) . 



tures sub-terminal $ NG 1NAB 



Encrusting, cells tubular, of equal diameter, dis- ) ~ 



tinct, sometimes ramous . } Tubulipora. . 



Encrusting, cells tubular, of equal diameter, co- J ^ 



alescent ] Uiscopora . . 



Encrusting, cells elliptical, linked together like beads Hippothoa . . 



Encrusting, cells oval, with contracted terminal ) T 



, s ' \ Lepralia. . . 



apertures $ 



Encrusting, cells oval, with calcareous or ossified \ ., 



rims, apertures patulous \ ' A p A ' 



Encrusting, cells quadrangular or hexagonal . . . Flustra . . . 



***** Polypidoms spongy. 

 Cells immersed, irregular, with contractile apertures Alcyonidium . 

 Cells in tubes Crystatella . 



37 



40 



55 



55 

 55 



71 

 130 



131 



129 



109 



97 



126 



100 



102 



103 



108 

 101 

 113 



118 

 121 



132 



