178 



SYNDICTYON EETICULATUM. 



diameter. The young Medusoa resemble somewhat Zanclea (Fig. 291), 

 having the lasso-cells of the marginal tentacles arranged spirally in 

 large clusters oit the surface of the tentacles ; the more advanced 

 Meduste lose this character. The bunches of lasso-cells increase in size 

 towards the extremity, where the tentacle terminates in a club-shaped 

 bunch (Fig. 292) larger than the others; the sensitive bulb is large, the 



Fig. 291. 



ocellus at the base of the tentacle (Fig. 293) is similar to that of Sarsia, 

 the spherosome is of a uniform thickness, and the proboscis (Fig. 294) 

 resembles somewhat that of Dipurena ; the whole surface of the sphero- 

 some is covered with clusters of large lasso-cells (Fig. 296), giving 

 it a granulated appearance ; the ground-work consists of minute gran- 

 ulation, which appears under a low magnifying power to be arranged 



Fig. 290. Hydromedusarium of Syndictyon reticulatum, greatly magnified. 



Fig. 291. Syndictyon reticulatum, immediately after it has become freed from the Hydrome- 



dusarium ; in profile, magnified. 



Fig. 292. One of the tentacles of Fig. 291, magnified. 



Fig. 293. Sensitive bulb of Fig. 291. 



Fig. 294. Digestive cavity of Fig. 291. 



Fiff. 295. Fig. 291, from the actinal side. 



