xu THE VOYAGE OF H.M.S. CHALLENGER. 



§ 13. Hypothetical Ancestral Tree of the Acraspedse (Monophyletic). 



IV. 

 DISCOMEDUSVE 



II. 



PEROMEDUSjE. 

 i * \ 



PeRIPHYLLID/B 



IV. C. Ehizostom^i 



CkambessidjE 

 Versuridj: Leptobrachida; 



Stylorhizidse 



Crossostomidaj 



Pericolpidje 

 (Pericolpa) 



Pericolpida? 



{Pericolpa*) 



[Ancestral form of 



the Perornedusa?.] 



Himantostomida! 

 Eucrambessida? 



Pilemid^: 

 Eupilemidai 



Stomolophidoa 

 Lychnorhizidae 



III. 



CUBOMEDUSiE 



Chirodropid,e 



TOREUMID2E 



Polyrhizidje 



Polyclonidae 



Haplorhizidre 



CHARYBDEID.fi 



Tamoyidae 



Archirhizida; 

 (Archirhiza*) 



IV. B. Semostom^e 



I. 



STAUROMEDUSjE 



ltjcernarid.e 

 Halicyathidse 



Haliclystida? 



Tesserid^ 

 Depastridae 



Tesseranthidae 



(Tessera*) 



[Ancestral form of 



the Stauromedusa;] 



ULMARID.E 



Aurelida? 



Sthenonidre 



Ctaneid^; 

 Drymonemidae 



Umbrosida? 

 ( Ulinaris) 



Flosoitlid^! 

 (Floseula) 



Pateridas 

 I 



Medoridoj 

 (Procyanca) 



Pelagid^! 

 (Pelagia*) 



IV. A. Cannostom^: 



LlNERGIDffi 



EpHYRiDiB Liuuchidae 



Collaspidae 



TTausithoidaa 

 I 



Linanthida? 

 I 



Palephyridae 



(Ephyra*) 



[Ancestral form of the 



Discomedusa;] 



Procharagmida; 



(ProcJiaragma*) 

 [Ancestral form of 

 the Cuboniedusae] 



Tesserid^: 



Common ancestral form of all Acraspeda; or Seyphoniedusse 

 Tessera 



rC o r a l l a :" 

 LAnthozoa. 



-Scyphopolypi (Ancestral form of all Scyphopolypi : Scyphostoma) 



Hydropolypi- 



Hydropolypi 



-ARCHYDKA (Ancestral form of all Cnidariaj) 



Gastr.s:a (Ancestral form of all Metazoa) 



