120 STATES OF INSECTS. 



except some of the order Diptera, are provided with a 

 distinct upper-lip, for retaining their food during masti- 

 cation. As the construction of this part does not widely 

 differ from that of the perfect insect, which will hereafter 

 be more fully described, it is only necessary to observe, 

 that it is usually a transverse moveable plate, attached 

 posteriorly to the nasus [clypeus F.), and situated just 

 above the mandibles a . 



Upper-jaws (Mandibul.e). The most usual figure of 

 these, which are of a hard horny consistence b , is that of 

 two slightly concave, oblong, or triangular plates, often 

 at their lower extremity of considerable thickness, and of 

 very irregular form, the base of which is filled with 

 powerful muscles, and planted in the side of the mouth 

 so as to move transversely. The other extremity can be 

 made to meet or diverge like the claws of pincers, and 

 are divided into one or more tooth-like indentations, by 

 means of winch the food of the larva is cut c . This is 

 their construction in the larvae of all Lejndoptera, and in 

 many of those of the other orders. They frequently, 

 however, assume a different form, though their situation 

 is always the same. Thus in the larvae of the Capricorn 

 beetles {Ceranibyx L.) and of other wood-boring species, 

 they are shaped like the half of a cone, the inner sides of 

 which, applying close to each other, form a pair of power- 

 ful grindstones, capable of comminuting the hardest tim- 



a Lyonnet, t. \.f. 7. e. In the larva of Callidium violaceum, how- 

 ever, this part is of a singular shape, being orbicular. Kirby Linn. 

 Trans, v. I. xii./. 12. a. 



b It is affirmed ("iV. Diet. cVHist. Nat. vii. 333) that the larvae of 

 those Coleoplera that live in carcases have mandibles almost mem- 

 branous : those, however, of that of Silpha rugosa are horny and 

 hard. 



c Lyonnet, /. luf. 1. r> d, and/. 2, 3, 4. 



