78 HISTORY OF BRITISH ZOOPHYTES. 



FtOinilj I. Polypes naked, or with oulj a rudimentary po- 

 lypidoni. Corynid^e. 

 t Polypes naked. 



The tentacula scattered. Clava. 

 The tentacula in one row. Hydractinia. 

 tt Polypes with a horny cuticle. 



The tentacula with globose tips. Cory'ne. 

 The tentacula filiform. Cordylophora. 

 Family II. Polypidom fistular ; the tentacula whorled. 

 Tubulariad^e. 

 t The tentacula in a single whorl. Eudendrium. 

 tt The tentacula in a double whorl. 

 Polypidom rooted. Tubularia. 

 Polypidom unrooted. Corymorpha. 

 ■^■^ Ovisacs in the form of horny capsules or vesicles scat- 

 tered on the polypidoms, and deciduous. Sertula- 

 RINA, Ehrenherg. 

 Family III. Cells of the polypes sessile. Sertulariad/e. 

 t Cells biserial. 



Cells alternate, tubular. Halecium. 

 Cells vasiform, everted. Sertularia. 

 Cells conico-tubular, appressed. Thuiarta. 

 tt Cells uniserial. 



