CCELENTERATA, 



249 



fringed with tentacles, furnished with stinging thread- 

 cells. The radiating parts are in multiples of four. 

 Around the rim are minute -colored 

 spots, the " eye - specks." In fine 

 weather, these " sea - blubbers " are 

 seen floating on the sea, mouth down- 

 ward, moving about by flapping their 

 sides, like the opening and shutting 

 of an umbrella, with great regular- 

 ity. They are frequently phospho- 

 rescent when disturbed. Some are 

 quite small, resembling little glass 

 bells ; the common Aurelia is over a 

 foot in diameter when full-grown; Fig .i 96 ._a Medusa, seen in 

 while the Cyanea, the giant among P' ofi,e aud ^ ^ el ? w ' 



* ° showing central polypite, 



Jelly-fishes, Sometimes measures eight radiating and marginal 



feet in diameter, with tentacles one 



hundred feet long. When dried, nothing is left but a 



film of membrane weighing only a few grains. 



There are two representative types : the Lucemaria, 

 the Umbrella-acaleph, having a short pedicel on the back 

 . 009, for attachment: tentacles 



disposed in eight groups 

 around the margin, the 

 eight points alternating 

 with the four partitions 

 of the body -cavity and 



Fig. 19T. —Lucemaria auricula attached to a the four COl'IierS of the 

 piece of sea-weed; natural size. The one on , -, * 



the right is abnormal, having a ninth tuft of HI OU til J not leSS thai! 



tentacles * eight radiating canals, 



and no membranous veil. The common species on the 

 Atlantic shore, generally found attached to eel-grass, is an 

 inch in diameter, of a green color. Discophora, the ordi- 

 nary Jelly-fish, is free and oceanic. It differs from the 

 Lucemaria in its usually larger size and solid disk, four 



