178 



SYNDICTYON RETICULATUM. 



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

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

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

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

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

 bunch (Fig. 292) lai-ger than the others; the sensitive bulb is large, the 



Fig. 293. 



Fig. 290. 



Fig. 291. 



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

 the spherosome is of a iniiform 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. 293. 



Fig. 294. 



Fig. 290. Ilyilromctlusarium of Syndietvon retioulatiim, greatly magnified. 



Fig. 2UI. Syndiotyon retioulatnm, iimncdiatfly aftor it Las become treed from the Ilydromc- 

 dusarium ; in profile, magnified. 



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



Fig. 293. Sensitive bulb of Fig. 291. 



Fig. 294. Digestive cavity of Fig. 291. 



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



