At this stage the rhopalia have come to lie, as in the 

 adult, wholly within the margin of the umbrella and project 

 from its subiimbrella sm^face. The interrhopalial tentacles 

 have totally disappeared. The lines of adhesion separating 

 the radial canals are faintly visible as radiating lines of 

 greater transparency. The four lips of the mouth are spread 

 out into a cross -shaped figure and one may look directly through 

 the lumen of the oesophagus into the stomach, and see four gas- 

 tric filaments. Fig. 21. 



Each one of the four lips is nearly square and from its 

 two outer angles there are two grooves that extend obliquely 

 inward until they meet and form a V. The point of the V. is 

 in an ar^le of the oesophagus along which there is a groove 

 that is continuous with these other two grooves and extends 

 into the stomach. On the interradial side of each of the 

 eight labial grooves there may be seen a snail roughly circular 

 area that is less transparent than the rest. Tliese areas 

 are the nettle batteries first seen in earlier stages. The 

 margins of the lips are provided with numerous small processes, 

 the digitella. These are arranged in a single continuous se- 

 ries. 



The medusa from the strobila Fig. 19, was examined a few 



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