FRESH-WATER JELLY-FISHES. 19 
NoTe.—In specimens of Aurelia, 95.84 per cent of the animal is 
water; the solid matter in any jelly-fish is rarely over five per cent of 
the whole. 
Fresh-Water Jelly-Fishes.—These have recently 
been discovered in England. They are one third of an 
Fic. 18.—A jelly-fish swimming (Pé/agia). 
inch in diameter, and probably come from some warm 
climate, as they are active only when the temperature of 
the water is about 85°. 
