ACTINOZOA. 



215 



often, it is wanting. In Cyathophyllum and 

 certain allied forms there is a spurious columella 

 formed by the " twisting together " of the inner 

 edges of the septa. 



In Cystiphyllum neither columella, septa, nor 

 tabulae can be distinguished. The whole interior 

 of the corallite, save its shallow calice, is here, as 



Fig. 38. 



Zaphbentis cyxindrica. 

 (Part of a corallite, of the natural size.) 



it were, broken up b}^ the numerous laminae of a 

 sclerenchymatous deposit resembling the vesicular 

 substance of its epitheca and wall. 



Most Rugosa belong to the large group of 

 Cyathophyllidce, The remaining families include 

 but a few generic forms. 



Order EUGOSA. 



Family i. Staurid^. 



Gorallum simple or composite. Septa 

 complete, united by lamellar dissepiments. 

 p 4 



