Introduction to Annual ^[orphology. 1 15 



Thalassianthinae tentacles all compound, outer hooked, 

 papillose (Heterodactyla), or the inner with rounded warts 

 (Sarcophianthus). The stem of the branched tentacles mav 

 be warty Thymanthus), or ii lamented (Actineria) ; the branches 

 may be pear-shaped (Actinodendron), or feathery (Thalas- 

 siantl 



Order 2. Sclerodermata (Madreporaria) colonies, 

 rarely simple; skeleton enderonic, continuous, cal- 

 careous, with hexameral symmetry ;tetrameral in 

 Rugosa). This includes the reef-building corals of 

 past and present ages. 



following sub-orders are included : i. Rugosa (sur- 

 ;d to belong to Hydrozoa allied toMilleporidae), Palaeozoic" 1 



with theca?, complete tabula) and rudimental, or perfect im- 

 . without synapticulae ; in multiples of four. 

 nmchyma, and increase by parietal or 

 ular budding, not by fission. Four families are con- 

 tained: i. Stauridx simple or branched, with incomplete 

 . by lamellar dissepiments, the lour primary septa 

 . :. 'liaxonidaj simple, with complete 

 !al groo\ i>imcnts and tabula? none. 



hyllida,- simple, vesicular, with slight septa, and 

 bladder-like end : sometimes an operculum to the 



--... Cyathophyllidae simple or branched, with incoin- 

 :.nd tabuke ; cmlotheca: closing the chambers; 

 .: (Axophyllinac), or none ; septa regular 

 .tho{)hyllina.'), or irregular (Xaphrcntimv). The. Devonian 



i one, ( i(Hiioi)hylhim of four 

 vah 



ilata hexameral corals with tabula; ami 



. including the families :i . Seriato- 



. hyma abuiulant. (-(impact; septa 



:nbers filled by the thick 



wall :ni'-lla : \. the Red 



B unite.! to ili,-ir 

 . ith little iln- 



til. 



