132 



MELICERTUM CAMPANULA. 



Fig. 203 only a somewhat younger form of the same Medusa. We 

 have thus estabhshecl, by the observation of this Medusa, as well as 

 from the Aoung Hydrai'ium of Melicertum and Lafoea, the probable 

 character of the Hydrarium from which Melicertum, Staurophora. and 

 those Modus* which have no marginal capsules, are developed ; show- 

 ing that they hold an intermediate position between the Campauu- 



Fig. 203. 



larians and the Tubularians, being more closely allied to the latter in 

 their embryonic condition, and assuming as adult Moduste somewhat the 

 aspect of Campanularian Medusa?. The Trichjdra jmdica of \yright 

 is also closely allied to Lafoea and Staurophora. In the young Medusa 

 we have at first only two primary tentacles (Fig. 204) and two rudi- 

 mentary ones, and in the next stage there are sixteen. (Fig. 205.) 



The presence of eye-specks at the base of the tentacles of the young 

 Meduste of Lafoea calcarata and of Stauroj^hora laciniata are the surest 

 means of distinguishing them with accuracv. The differences in the 



DO ..' 



Pig 205. shape of the bell between these youngest 



Medusa3 (Fig. 203) and somewhat older 

 stages (Fig. 205), are of a similar character 

 to tho.se we are familiar with among the 

 young Campanularian Medusa^ of other gen- 

 era. To judge from analogy, I strongly su.s- 

 pect that the young Medusa of Staurophora 

 will in its turn l)o a Medusa, similar to these 

 Lafoean forms, having at first Init two primary tentacles. In tlie next 



Fi;;. 203. Profile view of very young Medusa of Melicertum campanula ; Lafu;an like. Sec 

 Fig. 192. 



Fig. 204. Half the disk of the same, seen from tin' attinal polo. 



Fig. 20"). Young Melicertum, with only four completely tin-med cliymiferous tubes. Ic, fii-st 

 set of cliymiferous tubes ; 2c, second set ; 1, 2, 3, tentacles of the first, second, and third sets. 



