JELLY-FISH, ETC. 485 



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. 

 Somewhat higher up, between every two arms, a bud is to be found. None of the 



Clavatella (a, magnified ; b, nat. size). 



specimens of a certain size examined in May were without their six buds, these 

 being 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 fertilised eggs; even the Clavatella at 

 other seasons lays eggs. 



Creeping medusae are also found in deep seas, although their presence at great 

 depths would hardly be expected. Haeckel remarks that " few animals appear 

 less suited for deep-sea life than 

 the medusae, with their soft, 

 mucilaginous, watery bodies, 

 and their singular methods of 

 swimming ; nevertheless, a few 

 species sink down to great 

 depths." One of the most 

 interesting forms adapted for 

 deep-sea life is the Pectis 

 antarctica, belonging to the 

 family of the Pectinidce. This 

 animal is remarkable for its Pectis (nat. size), 



sucker -tentacles, which stand 



in numbers round the margin of the firm cartilaginous disc (these in the illustra- 

 tion are represented in a contracted condition). These tentacles bear a great 



