CANNOSTOMAE SEMOSTOMAE KHIZOSTOMAE. 167 



the eight secondary radial canals (adradial) are unbranched. The 

 parts of the stomach from which the eight adradial and the four 

 interradial canals arise are pouched outwards. 



Sub-order 1. CANNOSTOMAE. 



With simple quadrangular manubrium without oral arms ; with short solid 

 marginal tentacles. 



Fam. 7. Ephyridae. Usually 16 wide gastric pouches, rarely 32-64, without 

 terminal branches ; usually 8 rhopalia, rarely 16-32 ; usually 16, rarely 32-64 

 marginal lobes. This family may be described as consisting of sexually mature 

 Ephyrae. Ephyra Per. and Les. ; Palephyra H. ; Zonephyra H.; Nausicaa H. ; 

 Nausithoe Kolliker ; Nauphanta H. ; Atolla H. ; Collaspis H. 



Fam. 8. Linergidae. With wide radial gastric pouches, and branched, blind 

 lobe-canals ; without circular canal. Linantha H. ; Linerges H. ; Liniscus H. ; 

 Linuche Esch. 



Sub-order 2. SEMOSTOMAE. 



With 4 large perradial oral arms, and with long hollow tentacles. 



Fam. 9. Pelagidae. Semostomae with 16 simple wide gastric pouches, 

 without branched distal canals, without circular canal. PelagiaPer. and Les., 

 with 8 adradial tentacles, 8 rhopalia, and 16 marginal lobes ; Chrysaora Per. 

 and Les. , with 24 tentacles (and 8 rhopalia), and 32 marginal lobes ; Dacty- 

 lometra L. Ag. 



Fam. 10. Cyaneidae. Semostomae with 16 or 32 wide gastral pouches, and 

 branched, blind lobe-canals, without circular canal. 16-32 or more marginal 

 lobes ; 8 or 16 rhopalia (4 per-, 4 inter-, and 8 adradial) ; 8 or more long hollow 

 tentacles. Procyanea H.; Medora Couthouy; Stenoptycha L. Ag.; Desmonema 

 L. Ag. ; Cyanea Per. and Les. ; Patera Lesson ; Melusina H. 



Fam. 11. Flosculidae. Semostomae with 16 or more simple unbranched 

 narrow radial canals and with a circular canal. 8 rhopalia ; 8-24 or more 

 long hollow tentacles. Floscula H. ; Floresca H. 



Fam. 12. Ulmaridae. Semostomae with 16 or more narrow radial canals, 

 which branch and often anastomose, and are connected by a circular canal. 

 8 or 16 rhopalia; 8-24 or more hollow tentacles. Ulmaris H.; Umbrosa H. ; 

 Undosa H. ; Sthenonia Esch. ; Phacellophora Brandt ; Aurelia Per. and Les. ; 

 Aurosa H. 



Sub-order 3. KHIZOSTOMAE.* 



With 8 large adradial, root-like, simple or branched, oral arms, with numerous 

 suctorial mouths, without central mouth opening, and without marginal 

 tentacles. 



Fam. 13. Toreumidae. Rhizostomae with 4 separated subgenital pits, and 

 with ventral suctorial frills on the 8 oral arms (no dorsal frills). 8, 12, or 16 

 rhopalia ; 8-16 or more narrow radial canals, branched and anastomosing. 

 Archirhiza H. ; Toreuma H. ; Polydonia L. Ag. ; Cassiopea Per. and Les.; 

 Cephea Per. and Les. ; Polyrhiza L. Ag. 



Fam. 14. Pilemidae. Rhizostomae with 4 separated subgenital pits, and 

 with dorsal as well as ventral sucking frills on the 8 oral arms. 8 rhopalia ; 

 8-16 or more branched and anastomosing radial canals, with circular canal. 



* The forms commonly called by the generic name Rhizostoma belong to the 

 genus Pilema. The term Rhizostomae is kept for the sub-order. 



