1 34 COELENTERATA. 



Sub-fara. 1. Laodicidae. With 4 radial canals and 4 gonads. Tetranema 

 H. ; Dissonema H. ; Octonema H. ; Thaumantias Eschsch. ; StaurostomaH.; 

 Laodice Lesson. 



Sub-fam. 2. Melicertidae. With 8 radial canals and 8 gonads. Meli- 

 certella H. ; Melicertissa H. ; Melicertum A. Ag. ; Mdicertidium H. 



Sub-fam. 3. Orchistomidae. With numerous radial canals. Orchis- 

 tomn H. 



Fani. 2. Cannotidae. Without marginal vesicles, with 4 or 6 radial canals 

 which are branched, bifurcated, or pinnate. Development unknown. 



Sub-fam. 1. Polyorchidae. With 4 or 8 pinnate radial canals, the side 

 branches ending blindly. Staurodiscus H. ; Gonynema A. Ag. ; Ptychogcna 

 A. Ag. ; Staunyrfwra Brandt ; Polyorchis A. Ag. 



Sub-fam. 2. Berenicidae. With 4 or 6 branched radial canals, branches 

 and main canals open into circular canal. Cannota H. ; Dyscannota H. ; 

 Berenice Peron and Lesueur ; Dipleurosoma Axel Boeck. 



Sub-fam. 3. Williadae. AVith 4 or 6 bifurcated radial canals, the 

 branches only open into circular canals. Dicranocanna H.; Toxorchis H. ; 

 Willctta H. ; Willia Forbes ; Probosddactyln Brandt ; Cladocanna H. 



Fam. 3. Eucopidae. With marginal vesicles and 4 simple nnbranched radial 

 canals, in whose course 4 or 8 gonads lie. The polyps when known belong to 

 the genera Campanularia, Obelaria, Clytia, Campanulina, etc. 



Sub-fam. 1. Obelidae. 8 adradial marginal vesicles, stomach without 

 stalk. Eucopium H. ; Saphcnella H. ; Eucope Gegenbaur ; Obelia Peron and 

 Les. (Fig. 115) ; Tiaropsis L. Ag. ; Euchilota McCrady. 



Sub-fam. 2. Phialidae. Numerous marginal vesicles, stomach without 

 stalk. PhiaHum H. ; Phialis H. ; Mitrocomium H. ; Epenthcsis McCrady ; 

 Mitrocomella H. ; Phialidium Leuckart ; Mitrocoma H. 



Sub-fam. 3. Eutimidae. 8 adradial marginal vesicles, a distinct, often 

 long, stomach-stalk. Eutimium H. ; Eutima McCrady ; Saphenia Eschsch.; 

 Eutimcta H. ; Eutimalplics H. ; Octorchidium H.; Octorchis H.; Octor- 

 chandra H. 



Sub-fam. 4. Irenidae. Xumerous marginal vesicles, a distinct stomach- 

 stalk. Irenium H. ; Irene Esch. ; Tima Esch. 



Fam. 4. Aequoridae. With marginal vesicles and with numerous (often 

 over 100) simple or branched radial canals. Polyp of Polycanna (Zygodactyla) 

 vitrina only known as a very small Campanaria. 



Sub-fam. 1. Octocannidae. With 8 simple radial canals. Octocanna H. 

 Sub-fam. 2. Zygocannidae. With 8 or more radial canals bifurcated at 

 their base. Zygocanna H. ; Zygocannota H.; Zygocannula H. ; Halopsis 

 A. Ag. 



Sub-fam. 3. Polycannidae. AVith numerous simple radial canals which 

 arise separately from the stomach (12 or more to over 100). Acquorea 

 Peron and Les. ; Rhcgmatodcs A. Ag. ; Stomobracliium Brandt ; Stauro- 

 brachium H.; Mesonema Esch.; Polycanna H. 



Limnocodium,* a fresh-water medusa from the Victoria Regia tanks of the 

 Royal Botanic Society, London, and of unknown habitat, is probably allied 

 here. 



* G. H. Fowler, Quart. J. Me. Sei., vol. 30, 1889, p. 507. 



