IV 



PHYLUM OELENTERATA 



in 



FIG. 52. Aurelia aurita. development A, planula: B, C, formation of the gullet 

 or stomodaeum; D, transverse section of youn scyphula; E, scyphula; F, 

 longitudinal section of same', G, division of scypnnla into ephyrulae; H, ephy- 

 rula from the side: I, the same from beneath. In AD and F the ectoderm 

 is unshaded, the endoHerm striated, and the mesoglcea dotted, a, lobes of 

 umbrell<; mnb, manubrium; wM, mouth; s f, septal funnel; st, stomodaeum; 

 t, tentacle: in, taenioles, or gastric ridges. (From Korschelt and Heider's 

 Embryology ) 



