154 



BOUGAINVILLIA SUPERCILTARIS. 



pable of expansion and contraction. In Figs. 236, 237, which are some- 

 what older Medusae in different attitudes, the digestive cavity is well 



Fig. 233. 



Fig. 235. 



Fig. 234. 



developed, and from the four corners of the actinostome bulge out four 

 club-shaped appendages, the first traces of the oral tentacles. There 



Fig. 238. 



Fig. 2.37. 



are two well-developed tentacles, which were at first a mere knob, with 

 distinct eye-specks. (Fig. 234.) The l)ell is quite thin at this stage, and 



Fi<;. 233. Hyilromcdusarlum of Bougaiuvillia supcrciliaris. 



Fig. 234. Young elongated Medusa. 



Fig. 235. Somewhat more advanced than Fig. 234. 



Fig. 236. Appearance a short time before separating from the stem, in a contracted state. 



Fig. 237. Tlie same as Fig. 23G, expanded. 



Fig. 238. Young Bougainvillia, immediately after its liberation from the llydromedusarium. 



