brella are f irst^noticed at the time when the rhopalial tenta- 

 cles begin to be absorbed. They are tiien feeble and at long 

 intervals. At the stage now before us, these movements are 

 rapid and violent and the rhytlim of movement is interinipted by 

 few pauses, ai-d these are short. The medusa was set free du- 

 ring the night after this drawing was made. The following 

 morning the basal segment had the appearance sho^vn in Fig. 20. 

 It is a scyphistoma with seventeen tentacles, but the mouth is 

 merely an orifice lefL after the detachment of the medusa. The 

 proboscis is not formed yet. I found many scyphistomas that, 

 from the large size of the stem and sraallness of the calyx, I 

 concluded had undergone strobilization and I have no doubt that 

 regeneration and strobilization are repeated a number of times. 

 At any rate, I am certain that the basal segment becomes a ful- 

 ly foiTOed sc^q^hi stoma. 



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