850 



THE INHABITANTS OF THE SEA, 



of the bell, and thus concentrating its efforts upon a narrower 

 space. More or less numerous tentacles generally depend from 

 the margin, and around it are disposed two kinds of remarkable 

 bodies — " vesicles " and " pigment spots," or " eye-specks " — 

 which are supposed to be able to communicate the impressions 

 of light and sound. This complexity of organisation in crea- 

 tures which Eeaumur contemptuously styled mere lumps of 

 animated jelly is all the more wonderful when we consider that 

 they consist almost entirely of water, and shrink to a mere 

 nothing when abandoned by their vital power. Thus of a 

 medusa originally weighing many pounds but few traces remain 



Various forms of Medusidap.. 



Aeqvorea formota, seen In profile. 6. The same, viewed from above, c. Upper view of WQltia 

 tteUata. d. Slabberia arnica, e. Portion of the marginal canal of Ttaropttt PattirtonU. 

 f. Polypite of Bougainville u dinema. g. Part of its marginal canal. *. Steetutrupia Owmtl. 

 (a, b, and d are about the natural size ; the others are magnified.) 



after death ; the ground is covered with a light varnish ; all the 

 rest has been absorbed by the thirsty sands. 



The oceanic or free-swimming forms of the LucernaridsB 

 resemble the Medusidse by their bell-shaped umbrella, but 

 differ from them by their internal structure, by the absence of 

 a marginal veil, by the nature of their canal system and mar- 

 ginal bodies, and by their mode of development. The radiating 

 canals, never less than eight in number, send off numerous 

 branches, which form a very intricate network, and the vesicles 



