120 STATES OF INSEcTS. (Larva.) 
in most Diptera. Each of these parts require separate 
notice. 
Upper-lip(Lasrum). The mouth of almost all larvae, 
except some of the order Diptera, are provided with a 
distinct wpper-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*. 
Upper-jaws (ManpisuLz). ‘The most usual figure of 
these, which are of a hard horny consistence®, 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 which the food of the larva is cut®. This is 
their construction in the larvee of all Lepidoptera, 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 larve of the capricorn 
beetles (Cerambyx L.) and of other wood-boring species, 
they are shaped like the half of a cone, the inner sides of 
* Lyonnet, t.1.f.7.£. Inthe larva of Callidium violaceum, how- 
ever, this part is of a singular shape, being orbicular. Kirby Linn. 
Trans. V.t. xi. f. 12. a. 
> It is afirmed (N. Dict. d Hist. Nat. vii. 333) that the larve of 
those Coleoptera that live in carcases have mandibles almost mem- 
branous: those, however, of that of Silpha rugosa are horny and 
hard. * Lyonnet, ¢. ii. f. 1. pp, and f. 2, 3, 4. 
