HYDFvOZOA. 



113 



seven definable families, whose characters may be 

 stated thus : — 



Order PHYSOPHOEIDiE. 



Family i. Apolemiad^i. 



Pneumatocyst small. Coenosarc filiform. 



Necto calyces and hydrophyllia present ; the 

 latter united with the other appendages into 

 groups, arranged at distant intervals along the 

 coenosarc. 



Tentacula without lateral branches. 



Family 2. Stepiianomiad^e. 



Pneumatocyst small. Coenosarc filiform. 



Nectocalyces and hydrophyllia present ; the 

 latter arranged with the other appendages in 

 continuous series. 



Tentacula with lateral branches, terminated 

 by sacculi. 



Family 3. Physophoriadjs. 



Pneumatocyst small. Coenosarc filiform, 

 but short, and dilated at its distal end. 



Nectocalyces present, occupying most of 

 the coenosarc below the pneumatophore. No 

 hydrophyllia. 



Tentacida with branches and in volu crate 

 sacculi. 



Family 4. Athorybiadje. 



Pneumatocyst occupying almost the whole 

 of the globular coenosarc. 

 Nectocalyces absent. Hydrophyllia. 

 Tentacula with branches and involucrate 



sacculi, each having two filaments and 

 median lobe. 



I 



a 



