102 NUTRITION. 



(Echinus,) this apparatus, which has been called Aristotle's 



Fig. 55. 



Fig. 56. 



lantern, (Fig. t 56,) consists of numerous pieces, and is much 

 more complicated. Still, the five fundamental pieces or jaws, 

 each of them bearing a tooth at its point, may be recognized, 

 as in Scutella ; only instead oT being placed horizontally, 

 they form an inverted pyramid. 



213. Among the Mollusks, a few, like the cuttle-fishes, 

 have solid jaws or beaks closely resembling 

 the beak of a parrot, (Fig. 

 57,) which move up and 

 down as in birds. But a 

 much larger number rasp 

 their food by means of a flat 

 Fig. 57. blade coiled up like a watch- Fig. 58. 



spring, the surface of which is covered with innumerable 

 minute tooth-like points of a horny consistence, as seen in a 

 highly magnified portion -of the so-called tongue of Natica, 

 (Fig. 58, a,) which, however, is only a modification of the 

 beaks of cuttle-fishes. 



214. The Articulata are remarkable, as 

 a class, for the diversity and complication 

 of their a^ paratus for taking and dividing 

 their food. In some marine worms, Nereis 

 for exarr pie, the jaws consist of a pair of 

 Fig. 59. curved, horny instruments, lodged in ~8 



sheath, (Fig. 59 ) In spiders, these jaws are external, and 



