BRANCH CCELENTER/1T/I : THE POLYPS, ETC. 



97 



water polyps, numer- 

 ous marine polyps, 

 many small jellyfishes 

 and a few corals ; (2) 

 the Scyphozoa, includ- 

 ing most of the large 

 jellyfishes; (3) the Ac - 

 tinozoa, including the 

 sea-anemones and 

 most "of the stony 

 corals; (4) the Cte- 

 nophora, including 

 certain peculiar jelly- 

 fishes. - 



The polyps, colonial 

 jellyfishes, etc. (Hy- 

 drozoa). To the class 

 Hydrozoa belongs the 

 Hydra already studied . 

 There are a few other 

 fresh-water polyps and 

 they all belong to this 

 class. The most in- 

 teresting members of 

 the class are the "co- 

 lonial jellyfishes," 

 constituting the order 

 Siphonophora. These 



FIG. 13. -The Portuguese M;m-of-War (Physalia sp.). (From specimen 



