JAWS OF ARTICULATA. 



109 



grasshopper, are delineated in their relative situa- 

 tions, but detached from one another, in Fig. 267. 

 The upper jaws (m), which are termed the mandi- 

 bles, are those principally employed for the masti- 

 cation of hard substances ; they are accordingly of 



greater strength than the lower jaws, and their 

 edges are generally deeply serrated, so as to act 

 like teeth in dividing and bruising the food. Some 

 of these teeth are pointed, others wedge-shaped, 

 and others broad, like grinders ; their form being 

 in each particular case adapted to the mechanical 

 texture of the substances to which they are de- 

 signed to be applied. Thus the mandibles of some 

 Melolonth(B have a projection, rendered rough by 

 numerous deep transverse furrows, converting it 

 into a file for wearing down the dry leaves, which 

 are their natural food.* In most cases, indeed, we 



duction to Entomology, vol. iii. p. 417, To the seven elements 

 above enumerated Savigny adds, in the Hemiptera, an eighth, 

 which he terms the Epiglossa. 

 * Knoch, quoted by Kirby. 



