206 ACTINOZOA. 



tive, the flattened base of each adhering at 

 pleasure. 

 Family 2. Ilyanthid^. 



Corallum not e^ddent. Polypes unat- 

 tached, with rounded or tapering base ; no 

 connecting coenosarc. 

 Family 3. Zoanthid^. 



Polypes attached, united by a coenosarc, 

 and furnished with a spicular corallum. 



Sub-order 2. Z. Sclerohasica. 



Family 4. Antipathid^. 



Corallmn sclerobasic, horny, smooth 

 or spinulous. Polypes with six tentacles. 

 Family 5. Htalochcetid^. 



Corallum sclerobasic, composed of twisted 

 siliceous fibres. Polypes with twenty ten- 

 tacles. 



Sub-order 3. Z. Sclerodermata, 



Tabulae present. Septa rudi- 

 mentary (Tabulaia) 2 



Tabulae alosent. ........ 5 



' Ccenenchyma "wanting, or ill- 

 developed . 3 



_ Ccenenchyma abundant. . . . . . .4 



Septa forming a spurious, mas- 

 sive cceneneliyma. . . Family 6. Thecid^. 

 _ Septa and corallites distinct. . Family 7. FAVOsiTiDiE. 

 ' Sclerenchyma compact. Coral- 

 lum arborescent. . . Family 8. Seeiatopoeidje. 

 SclerenchjTna tubular or cel- 

 lular. .... Family 9. Mellepoeid^. 



■ Septa indicated by faint striae 



(Tubulosa). . . . Family 10. AnopoEiD^. 



_ Septa well developed. . . . . . . .6 



' Sclerenchyma porous (Perfo- 

 rata) 7 



Sclerenchyma imperforate 



{Aporosa). ......... 8 



