PEDIGREE OF CCELENTERA, 



159 



we have jelly fish wholly free {Felagia), jelly fish with a 

 sedentary larval life (Aurelia), jelly fish predominantly pas- 

 sive {Lticernarid), and related polypes (Sea anemones, &c.), 

 which only occasionally rise into free activity; while in the 

 other series we have medusoid types always free (Trachy- 

 medusae), others which are liberated from (Campanularian 

 and Tubularian) sedentary hydroids, other (Sertularian and 

 Plumularian) zoophytes whose buds though often medusoid- 

 like are not set free, and finally. Hydra, which, though it 

 may creep on its side, or walk on its head, is predominantly 

 a sedentary animal, without any youthful free swimming 

 stage. It must be noticed that the most frequent larval 

 form is the planula, so that if we regard the gastrula as the 

 ancestral type, the life history is not here a recapitulation of 

 the race history. 



GENERAL SCHEME OF C(i:LENTERA. 



Predominantly Passive. 



Predomixantlv Active. 



C. Cte<->jophora, e.g., Beroe, 

 Venus' Girdie. 

 (Active climax.) 



C 11. Anthozoa or Aciinozoa. 

 (Zoantharia) Sea anemones 



and related corals. 

 (Alcyonaria) Dead Men's 



Fingers and related 



corals. 



The embryos are free swimmers, and a 

 few adults also are locomotor. 



E. 



SCYPHO--: 

 ZOA. 



y / Scj'phomedus^ or 

 ' ( Acraspeda. 

 c. Adult Lucernarians 



usually attached. 

 b. Sedentary larval stage. 

 a. No fixed stage. 



c. Free embryos. 



b. Aurella type of jelly fish. 

 a. Pelagia type of jelly fish. 



ANCESTRAL 



GASTR/EA. 



Y 



A. 



Hyoro- 



ZOA. 



1. No fixed stage. 



2. No fixed stage. 



3. Many Hydroid coloniee. 



(Campanularians and 

 Tubularians.) 



4. Many Hydroid colonies, 



whose reproductive per- 

 sons are not liberated. 



5. Coralline Millepores. 



6. Hydra without any specially 



. Trachymedus^ (always locomotor). 



. Siphonophora: (locomotor colonies of 



modified medusoids). 

 . Liberated reproductive " persons " of 



these colonies. 



. No free stage, except as embryos. 



5. No known free stage. 

 locomotor stage. 



