70 THE OCEANIC HYDROZOA. 



I. Fam. APOLEMIAD^. 



PhysophoridEe provided with nectocalyces and hydrophyllia ; the latter united with the other 

 organs into groups, which are arranged at considerable intervals along the coenosarc. Tentacula without 

 lateral branches. Pneumatocyst small. Coenosarc filiform. 



Genus I. Apolemia [Eschsckolz). 

 A. iivaria. 



II. Fam. STEPHANOMIAD^. 



Physophoridse provided with nectocalyces and hydrophyllia; the latter arranged with the other 

 organs in a continuous series. Tentacula with lateral branches terminated by sacculi. Pneumatocyst 

 small. Ccenosarc filiform. 



A. Sacculi without involucra, and ending in a single filament. 



a. With biserial nectocalyces. 



Genus II. Halistemma [mihi). 



H. rubrum [elegans ?) 



b. With multiserial nectocalyces. 



Genus III. Forskalia [Kolliker). 

 F. contorta. 

 F. Edwardsii. 

 F. Ophiura. 

 * F. prolifera. 



B. Sacculi provided with involucra. Filament single. 



Genus IV. Stephanomia (Peron and Lesueur). 

 S. Ampkilridis. 

 a. Sacculi with involucra. Filaments two, with a median lobe. 



Genus V. Agalma {Eschsckolz). 



A. Sarsii. 

 A. clavatum. 

 A. Okenii. 



III. Fam. PHYSOPHORIAD^. 



PhysophoridiE with nectocalyces, but without hydrophyllia. The distal end of the filiform 

 coenosarc dilated. Tentacular branches with involucrate sacculi. Pneumatocyst small. 



Genus VI. Physofhora [Forskdt). 

 P. hydrostatica. 

 P. musonema 1 



