CCELENTERATA 115 



stony corals ; Scyphozoa, large jellyfishes, many of which do not 

 have the double form of development ; Actinozoa, the sea-anemones 

 and the different forms of stony corals, including sea-fans, sea- 

 pens, etc. ; Ctenophora, the jellyfishes commonly known as comb- 

 jellies. 



