HOW ANIMALS EAT. 



57 



The mouth of the Cuttle-fish is the most elevated type 

 below that of the Fishes. A broad circular lip nearly 

 conceals a pair of strong horny mandibles, not unlike the 

 beak of a parrot, but reversed, the upper mandible being 

 the shorter of the two, and the jaws, which are cartilagi- 

 nous, are imbedded in a mass of muscles, and move ver- 

 tically. Between them is a fleshy tongue covered with 

 teeth. 



The parasitic Worms, living within or on the outside 

 of other animals, generally have a sucker at one end or 

 underneath, serving simply for attachment, and another 

 which is perforated. The latter is a true suctorial mouth, 

 being the sole inlet of food. It is often surrounded with 

 hooklets or teeth, which serve both to scarify the victim 

 and secure a firm hold. In the Leech, the mouth is a 

 triangular opening w T ith thick lips, the upper one pro- 

 longed, and with three jaws. In many Worms it is a 

 fleshy tube, which can be drawn in or extended, like the 

 eye -stalks of the Snail, and contains a dental apparatus 

 inside (Fig. 17). 



Millepedes and Centipedes have two lateral jaws and a 

 four-lobed lip. 



In Lobsters and Crabs the mouth is situated underneath 

 the head, and consists of a soft upper lip, then a pair of 

 upper jaws provided w T ith a short feeler, below which is a 

 thin bifid lower lip ; then follow two pairs of membranous 

 under jaws, which are lobed and hairy ; and next, three 

 pairs of foot-jaws (Fig. 250). The Horse-shoe Crab has 

 no special jaws, the thighs answering the purpose. The 

 Barnacle has a prominent mouth, with three pairs of rudi- 

 mentary jaws. 



With few exceptions, the mouths of Insects in the lar- 

 val state are fitted only for biting, the two jaws being 

 horny shears. But in the winged, or perfect, state, Insects 

 may be divided into the masticating (as the Beetle) and 



