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University of California Public at ions. 



[Zoology 



V. — Development of the Tentacles. 



The development of the tentacles, with the typical irregulari- 

 ties, is illustrated in the accompanying nine series of diagrams 



]<^ig. 12. Two views of the same larva, from life, showing the clear sepa- 

 ration of stem and hydranth, and the beginnings of tentacles. 



Fig. 13. Larva with 3 distal tentacles showing endodermal ridge be- 

 tween cavities of hydranth and stem. X 135. 



(Fig. 14). The numerals indicate order of appearance, Arabic 

 standing for distal, Roman for proximal tentacles. The dia- 



