PHYLUM CcELENTERATA 

 at sd 



Fig. 52. — Aurelia aurita, development. A, planula; B, C, formation of the gullet 

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

 longitudinal section of same; G, division of scyphula into ephyrula:; H, ephy- 

 rula from the side; I, the same from beneath. In A-D and F the ectoderm 

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

 umbrella; vnih, manubrium; mth i mouth; s f y septal funnel; st, stomodaum; 

 t, tentacle; tn y ta;nioles, or gastric ridges. (From Korschclt and Heider's 

 Embryology.') 



