ITS TENTACLES. 87 



May, I found the Sarsia even more abundant around 

 the boulders at the Nothe Point. They were ac- 

 cumulated by hundreds if not thousands, shooting 

 hither and thither near the surface of the clear -water, 

 in the narrow interstices of the rocks, and in the little 

 inlets, borne in by the incoming flood-tide. 



The size, the perfect transparency, the elegant form, 

 and the extraordinary vivacity of this species render 

 it one of the most interesting of the Medusae, for keep- 

 ing in a glass vessel of sea- water. Its shape is that 

 of an ellipse, of which about a third has been cut off 

 at one end ; a tall bell of the purest crystal, a little 

 narrowed at the mouth. At four equidistant points on 

 the margin of this bell are placed as many knobs, 

 within each of which is a bright red speck, and from 

 every one of the knobs depends a tentacle resem- 

 bling a slender thread. Often these threads are 

 shrivelled up till they are not more than a quarter of 

 an inch long ; more commonly they are about an inch 

 and a half in length, but occasionally, when the Sarsia 

 rests motionless in the water, a little turned over on 

 one side, its tentacles are allowed to hang down in the 

 deep to a great length ; five inches I have seen them 

 extended, as measured by a rule placed against the 

 side of the glass. When thus stretched they appear 

 like a thread of excessive tenuity, but if you look very 

 closely you may see even with the naked eye that it is 

 not a simple thread, but rather a string of the most 

 minute white beads, which when placed under the 

 microscope are discovered to be a series of thickened 

 knobs, arranged in an imperfect spiral round the crai- 

 tral filament. 



