222 THE CILIOGRADE ORDER. 



beautifully-illustrated history of the naked-eyed Me- 

 dusce is a model for future observers. 



The Jelly-fishes of another order called Ciliograde, 

 move from place to place by means of innumerable 

 vibratile hair-like organs, called cilia, variously disposed 

 on the surface of their body. The common JBeroe of our 

 shores offers a charming example of this sort of motion. 

 This little creature is met with in summer on most 

 parts of the coast, swimming near the surface, and may 

 readily be taken in a gauze drag-net. It has a melon- 

 shaped body, from half an inch to nearly an inch in 

 length, clear as crystal, and divided as it were into 

 gores by eight longitudinal equidistant bands or ribs. 

 These ribs when minutely examined are found clothed 

 with innumerable flat plates resembling the paddles 

 of a water-wheel, placed one above another and acting 

 under the control of the will of the animal. When the 

 Beroe wishes to move, these paddles are set in motion, 

 and by their united action on the water propel the living 

 globe of crystal with a swift and easy motion, forwards 

 or backwards as it wills; and when it wishes to turn, it 

 merely stops the movement of its paddles on one side. 

 The cilia, in sunlight, reflect brilliant prismatic colours 

 and in darkness flash with a beautiful blue light. De- 

 licate as are its organs of motion, the fishing apparatus 

 of the Beroe is not less elegant. This consists of two 

 long and exceedingly slender tentacula, five or six inches 

 in length when fully extended, but capable of being 

 wholly withdrawn within the body of the creature 

 where they are lodged in tubular sheaths. To the long 

 filament is attached, at regular distances, a multitude of 



