SYSTEMATIC ARRANGEMENT. 71 



IV. Fam. ATHORYBIAD^. 



Physopboridae without nectocalj^ces, and with hydrophyllia. Tentacular branches with involucrate 

 sacculi, with two filaments and a median lobe. Pneumatocyst occupying almost the whole of the 

 globular coenosarc. 



Genus VII. Athorybia (Eschscholz). 



A. rosacea. 

 A. melo. 



V. Fam. RHIZOPHYSIAD^. 



Pbysophoridae with a small pneumatocyst and a filiform coenosarc ; without either nectocalyces or 

 hydrophyllia, and having lateral branches without sacculi, to their tentacula. 



Genus VIII. Rhizophysa [Peron and Lesueur). 

 R. filiformis. 



VI. Fam. PHYSALIAD^. 



Pbysophoridae with a pneumatocyst which occupies almost the whole of the thick and irregularly 

 fusiform coenosarc; without cither nectocalyces or hydrophyllia; and without lateral branches to the 

 tentacula, which are provided with basal sacs. 



Genus IX. Physalia (Lamarck). 

 P. caravella. 



VII. Fam. VELELLID^. 



PhysophoridEe without nectocalyces or hydrophyllia; with short, clavate, simple, or branched, 

 submarginal tentacles. A single central, principal polypite. Pneumatocyst flattened, divided into 

 chambers by numerous concentric partitions, and occupying almost tlie whole of the discoidal coenosarc. 



a. Pneumatocyst cristate. Tentacula simple. 



Genus X. Velella {Lamarck). 



b. Pneumatocyst without a crest. Tentacula branched. 



Genus XI. Poupita [Lamarck). 



