INTRODUCTION. 



Iv 



Genera. 



1 , i Polypites on a distinct stem 15 



' ( Polypites sessile 16 



; Stems a simple tube (or rarely with 

 a single branch) TUBICLAVA. 

 Stems much branched and plant- 

 like CORDYLOPHORA. 



{ Tentacles few ; the four uppermost 

 long and erect TIRKIS. 



Tentacles very numerous CLAVA. 



I Polypites with a bilabiate mouth 



17. < (and two tentacles) LAR. 



( Polypites with a simple mouth . . 18 



[Tentacles with bosses formed of 

 -. Q \ large thread-cells placed a little 



' 1 above the base HYDRANTIIKA 



(Tentacles without bosses 19 



i q I Polypites sessile , 20 



' | Polypites on a distinct stem 22 



(Gonophoresborneonpolypiteswith- 



')() 3 out tentacles 21 



' j Gonophores borne on polypites with 

 ( tentacles or on the adherent base PODOCORYNE and 



CORYNOPSIS*. 



( Polypites supported on a chitiuous 



01 J and muricated crust HYDRACTINIA. 



" ' i Polypites developed on a simple 



( retiforni stolon CIONISTES. 



I Polypites with a trumpet-shaped 



22. <. proboscis EUDENDRIUM. 



| Polypites with a conical proboscis . 23 



( Body of polypite and lower part of 

 o ., J tentacles covered by a membra- 

 " ' 1 nous sheath BIMKRIA. 



( Polypites without such covering . . 24 



Gonophores borne on polypites 



24 without tentacles DICORYNE and HE- 



Gonophores borne on the ccenosarc. 25 TEROCORDYLE. 



1 More or less arborescent GARVEIA and Bou- 



25. ! GAINVILLIA. 



[ Small, and of simple habit AxRACTYLisand PE- 



RIGOXIMUS. 



* These genera diifer only in the character of the medusifonn zooid. 



