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 

 booklets or teeth, which serve both to scarify the victim 

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

 triangular opening with 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 with 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 



