462 



MEDUSAE OF THE WORLD. 



one of the 8 radial stomach-pouches. The root of each tentacle, where it fits into the 

 gelatinous substance of the exumbrella, is thus covered with two layers of ectoderm, one being 



Fio. 304. — Cunoclantha oclonaria, after Brooks, in Mem. Boston Soc. Nat. Hist., vol. 3. Showing development of actinula 



larva and young medusa. 

 A, young actinula. B and C, budding actinula? giving rise to medusa-buds. D t young medusa with only 4 tentacles. 



E, aboral view of young medusa. 



continuous with the general ectoderm covering the exumbrella and the other is continuous 

 with the ectoderm of the main shaft of the tentacle. The ectoderm of the shaft of each tentacle 



