MEGAZOOIDAL INDIVIDUALS 99 



a section of the organism would have been presumably like 

 Fig. 32 ; but in the primitive anemone's development X 

 was uncalled for, and one layer each of ectoderm and endo- 

 derm were all that was necessary to line each side of the 

 oesophageal walls ; the ectoderm from outside growing down 

 to line the gullet. 



THE MONO-MEGAZOOIDAL INDIVIDUAL OF 

 MEDUSOID PLAN. 



The Individual Medusa. 



The medusiform gonophore is, of course, only part of 

 an Individual, and in contrast we have the real Medusae 



Fig. 33. — Camarina (Geryonia) hastata, an Individual Medusa. 

 (After Nicholson.) b, radiating canal ; c, circular canal ; 

 s, sense-organ. 



which are complete Individuals and sexually reproduce 

 others like themselves without intervening zooidal colony 

 formation. Examples of such are the Trachymedusce. 



The fact that the structural plan of the Medusa is 



