THE JELLYFISH AND THEIR ALLIES 



3459 



claim our attention presently, but two remarkable forms, which have taken to creep- 

 ing on the ground, deserve attention. In Dalmatia, on seaweed, a delicate, pale 

 object can often be discerned with a magnifying glass creeping laboriously about on 

 its long arms. If detached from the seaweed, it falls to the bottom, as it is unable 

 to swim. In each point of its structure this animal is a medusa, related to the 

 genus Eleutheria, or Cladonema, but still further removed from the ordinary medusa 



Clavatella (a. magnified ; b. natural size). 



in one respect, since the Cladonema alternately swims and creeps. This creep- 

 ing medusa (Clavatella prolifera} has six arms, the tips of which are provided 

 with true suckers. On these it walks, as on stilts, while from each arm a 

 short stalk rises, the swollen end of which is beset with stinging capsules. 

 The very extensile mouth tube moves about tentatively, and easily seizes upon 

 the small crustaceans to be found upon the seaweed. Just above the base of 

 each arm lies a horseshoe-shaped eye-spot containing a well-developed lens, 

 but so far the nerve belonging to a true eye has not been discovered. Some- 

 what higher up, between every 

 two arms, a bud is to be found. 

 None of the specimens of a cer- 

 tain size examined in May were 

 without their six buds, these be- 

 ing at such different stages of 

 development that their gradual 

 growth could be clearly traced. 

 On the riper buds the rudiments 

 of a second generation of buds 

 were to be seen. Multiplication 

 by budding has been observed in 

 other medusae, and it is from 



such budding medusoid colonies that we may perhaps deduce the remarkable 

 swimming colonies of the Siphonophora. As a rule, however, all medusae multiply 

 sexually by means of fertilized eggs; even the Clavatella at other seasons lays eggs. 



Pectis (natural size). 



