206 ACTINOZOA. 



tive, the flattened base of each adhering at 

 pleasure. 

 Family 2. Ilyanthid^e. 



Gorallum not evident. Polypes unat- 

 tached, with rounded or tapering base ; no 

 connecting coenosarc. 

 Family 3. Zoanthid^e. 



Polypes attached, united by a coenosarc, 

 and furnished with a spicular corallum. 



Sub-order 2. Z. Sclerobasica. 

 Family 4. Antipathid^e. 



Corallum sclerobasic, horny, smooth 

 or spinulous. Polypes with six tentacles. 

 Family 5. Hyaloch(etid,e. 



^ Corallum sclerobasie, composed of twisted 



siliceous fibres. Polypes with twenty ten- 

 tacles. 



Sub-order 3. Z. Sclerodermata. 



{Tabulae present. Septa rudi- 

 mentary ( Tabulata) 2 

 Tabulae absent !!!'.$ 



{Ccenenchyma wanting, or ill- 

 developed 3 

 Ccenenchyma abundant, . [ \ 4 

 f Septa forming a spurious, mas- 

 * j sive ccenenchyma. . . Family 6. Thecid^. 

 L Septa and corallites distinct, . Family 7. Favositid^:. 



{Sclerenchyma compact. Coral- 

 lum arborescent, . . Family 8. Seriatopoeid^e. 

 Sclerenchyma tubular or cel- 

 ^ . . • . Family 9. Milleporid^e. 



J Septa indicated by faint strise 



5 1 (luozclosa). . „ m Family 10. Auloporid^e. 

 I Septa well developed 6 



{Sclerenchyma porous (Perfo- ' ' . 

 rata) . ........ 7 

 Sclerenchyma imperforate 

 (Aporosa) 8 



