206 ACTINOZOA. 



tive, the flattened base of each adhering at 

 pleasure. 

 Family 2. Ilyanthid^. 



Corallum not evddent. 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. Sclerobasica, 



Family 4. Antipathid^. 



Corallum sclerobasic, horny, smooth 

 or spinulous. Polypes with six tentacles. 

 Family 5. Hyalochcetid^. 



Corallum, sclerobasic, composed of twisted 

 siliceous fibres. Polypes with twenty ten- 

 tacles. 



Sub-order 3. Z. Sclerodermata. 



{Tabulse present. Septa rudi- 

 mentary (Tabulata) 2 

 Tabulse absent 5 



{Coenenchyma wanting, or ill- 

 developed 3 

 Coenenchyma abundant. 4 



f Septa forming a spurious, mas- 

 ^ < sive coenenchyma. . . Fami'y 6. Thecidje. 

 [_ Septa and coraUites distinct. . Family 7. Favositld^. 



{Sclerenchyma compact. Coral- 

 lum arborescent. . . Family 8. Seeiatopobid-ze. 

 Sclerenchyma tubular or cel- 

 lular. .... Family 9. MilleporidjE. 

 {Septa indicated by faint striae 

 (Tubulosa). . , . Family 10. Auloporidje. 

 Septa well developed 6 



{Sclerenchyma porous (Perfo- 

 ^^JJ^) • 7 

 Sclerenchyma imperforate 

 (Aporosa) 8 



