CCELENTERATA. 
249 
fringed with tentacles, furnished with stinging thread- 
cells. The radiating parts are in 
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 ; Fiq>196j _, 
multiples of four. 
■A Medusa, seen in 
profile and from below, 
showing central polypite, 
radiating and marginal 
canals. 
while the Cyanea , the giant among 
Jelly-fishes, sometimes measures eight 
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 Lucernaria , 
the Umbrella-acaleph, having a short pedicel on the back 
, for attachment; tentacles 
W* ««•*. disposed in eight groups 
around the margin, the 
eight points alternating 
with the four partitions 
of the body-cavity and 
the four corners of the 
mouth; not less than 
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. Diseophora , the ordi¬ 
nary Jelly-fish, is free and oceanic. It differs from the 
Lucernaria in its usually larger size and solid disk, four 
Fig. 19T .—Lucernaria auricula attached to a 
piece of sea-weed; natural size. The one on 
the right is abnormal, having a ninth tuft of 
tentacles. 
