72 STRUCTURAL AND SYSTEMATIC ZOOLOGY 



CLASS 2. Scyphozoa 



These are jellyfishes which are characterized mainly 

 by having reproductive glands which discharge their 

 contents into the stomach whence the reproductive cells 

 make their way out through the mouth, by having the 

 gastric cavity much branched and ramifying through 

 the gelatinous body, and by the presence of filaments 

 projecting into the gastric cavity. 



FIG. 22 Jellyfish (Pelagia noctiluca). Mediter- 

 ra nean. 



FIG. 23. Portuguese Man- 

 of-war (Physalia), \ nat- 

 ural size. Tropical Atlantic. 



The jellyfish has a soft, gelatinous, semitransparent, 

 umbrella-shaped body, with tubes radiating from the 

 central digestive cavity to the circumference, and with 

 the margin fringed with tentacles, which are furnished 



