1 TRIBE III.— MADREPORACEA. 



Tentacles in a single series, twelve (rarely more), some- 

 times obsolete : gemmiparous ; gemmation lateral : coral - 

 ligenous ; coraUum calcareous ; cells {calyces] quite small ; 

 rays {septa) six to twelve, or obsolete : interstitial surface 

 not lamello-striate. (Not British.) 



TRIBE IV.— ANTIPATHACEA. 



Animals with six tentacles, forming at the base horny 

 secretions (fleshy, enveloping a horny axis). (Not British.) 



TRIBE L— ASTR^E \CEA. 



ANALYSIS OF THE NON-CORALLIGENOUS FAMILIES. 



Base adherent at pleasure. 



Tentacles compound (Nut British} Metridiadce. 



Tentacles simple. 



Column pierced with loop-boles Sagartiada. 



Column imperforate. 

 Column smooth. 



Margin simple Antheadce. 



Margin beaded Actiniadce. 



Column warted Bunodidce. 



Base non-adberent. 



Lower extremity rounded, simple Ilyanthida. 



Lower extremity inclosing an air-chamber (Not British ) Minyadida. 



