CORAL-MAKERS AND JELLY-FISH 95 



in length, and the lips of the mouth are often drawn 

 out into a sort of depending trunk, or into four large 

 tapering lobes or lips of jelly, which, with the longer 

 tentacles, are used for seizing prey. The commonest 

 jelly-fish on our coast — so common as to be " the " jelly- 

 fish />ar exre//ence — is often to be seen left on the sands 

 by the receding tide or slowly swimming in quiet, clear 

 water at the mouth of a river in enormous numbers. 

 It is known as " Aurelia " (Fig. 7). It is as big as a 

 cheese-plate, and the four pouches connected with the 

 stomach are coloured pink or purple, and appear in the 

 middle of the circular plate of jelly, like a small Maltese 

 cross. The reproductive particles (germ-cells and sperm- 

 cells) are produced in that coloured region, and escape by 

 the mouth. There is a fringe of fine, very short tentacles 

 round the edge of the disk, and they, as well as the great 

 lobes of the mouth, are provided with innumerable coiled- 

 up stinging hairs or " thread-cells," similar to those of the 

 sea-anemones, which led Aristotle to call both groups 

 " sea-nettles." Eight stalked eyes are set at equal in- 

 tervals around the disk. 



Usually accompanying the floating crowd of the 

 common and abundant Aurelia are a few specimens 

 of a very unpleasant kind of Medusa of a turbid appear- 

 ance, often called " slime balls " by fishermen, from 

 six inches to a foot in diameter. It is known to 

 naturalists by the name " Cyanaea capillata." The 

 tentacles on the edge of the disk of this kind of jelly- 

 fish are very long and elastic, stretching to several feet, 

 even yards, in length, and are provided with very 

 powerful stinging hairs. The tentacles not infrequently 

 become coiled around the body of a bather ; the stinging 

 hairs are shot out of the little sacs in which they are 

 rolled up, and the result may be very painful to the 



