268 THE INHABITANTS OF THE SEA. 



been driven into its gaping portals, it is presently crushed be- 

 tween a pair of formidable sharp-toothed jaws, which are per- 

 petually in motion, whether the animal is taking food or not. 

 After having undergone the action of this lively apparatus, 

 the aliment passes into a tubular stomach surrounded by a 

 cushion-like mass of cells commonly coloured with the hue of 

 the food, and, therefore, concluded to be connected with **v 

 digestive system. 



ConochiluB volvox. — (Highly magnified.) 

 a. Jaws and teeth. b. Papillx. c. Glands. d. Ovarium. 



The rotifera are either naked or covered with a sheath, and 

 many inhabit a tube formed by themselves, attached by its 

 lower end to some water-plant, and open at the summit, from 

 which the animal protrudes when it would exercise its active 

 instincts, and into which it retires for repose from labour or for 

 refuge from alarm. The majority, however, have a furcated 

 foot,. which is often capable of contraction by a set of telescopic 

 sheathings or false joints, and by which they are enabled to 

 secure a hold of the minute stems of water-plants. This is 



