PHYLUM COELENTERATA 



133 



Obelia habit 



Mouth ■? 



tb/drotheca- 



Coelenteron ■'' 



hntoderm 



tctoderm 



Qonotheca 

 MedU5Q-bud 

 B\a5bo5t\/ie - 



Radiol canal ^^ 

 Repiroductive 



Moubh 7^^-tirf^ 



Jcatocyjfc— - 

 Tenbacles- 



Kedusa 



Obelia 



Fig. 58. — Obelia, hydrozoan colonial coelenterate, showing: asexual generation, 

 sexual generation (medusa), structure, and habit of life. (Courtesy of General 

 Biological Supply House.) 



