88 ITS PEDUNCLE. 



But the most remarkable and conspicuous feature 

 in this Medusa is the peduncle, which depends, like 

 the clapper of a bell, from the centre of the roof This 

 is a somewhat thick, fleshy, cylindrical organ, capable 

 of energetic movements, and particularly of enormous 

 elongation and contraction. Sometimes it is shortened 

 so as to he wholly contained in the concavity of the 

 bell, being more or less curled up at the same time ; 

 at others it is lengthened and allowed to protrude far 

 beyond the margin, hanging down, — not merely to 

 " twice the length of the body," as Professor Forbes 

 says ; — this gives a very inadequate idea of its powers, 

 but to five times that length. I carefully measured 

 one which was lying quite still, near the side of the 

 glass, (a vessel with straight sides, so that there was no 

 irregular refraction) by applying an ivory scale to it ; 

 the peduncle was twenty lines in length, though the bell 

 was scarcely four. The basal part of this long tongue is 

 abruptly diminished to a mere thread, and though this 

 is not conspicuous when the organ is contracted, it 

 becomes a marked character in the extended condi- 

 tion ; in the case I have just mentioned the thread- 

 like neck formed just one- third of the whole length, 

 itself reaching far beyond the margin of the bell. 



The motions of the Sarsia are more energetic than 

 those of any other Medusa that I am acquainted with. 

 In the unbounded freedom of their native sea, and in 

 the limited dimensions of a glass vase, they are alike 

 sprightly. By rapid pump-like contractions of their 

 umbrella, they dart through the water, and shoot round 

 and round, almost with the force and swiftness of a 

 swimming fish. The summit of the bell always goes 



