WITH ARTICULATED FEET. 
133 
especially named mandibles ; the pieces which cover them 
in front and rear, are named lips ; and that of the front in 
particular receives the name of labrum . This remark belongs 
more especially to the hexapod insects. Certain articulated 
filaments attached to the jaws, or the under lip, and which 
appear to serve the animal for the purpose of recognizing its 
food, are termed palpi , or antennulae . The forms of these 
various organs determine the nature of the aliment as pre- 
cisely as do the teeth of quadrupeds. To the lower lip the 
tongue, or ligula , commonly adheres. Sometimes (the bees 
and many other hymenopterous insects,) it is considerably 
prolonged, as well as the jaws, and forms a sort of false pro- 
boscis (promuscis) having the pharynx at its base, often 
covered by a species of sub-labrum, called by M. Savigny 
epipharynx . Sometimes (hemiptera and dipteral) the man- 
dibles and jaws are replaced by scaly pieces, in the form of 
bristles or lancets, received in a tubular elongated sheath, 
either cylindrical and articulated, or more or less elbowed, 
and terminated by sorts of lips. These parts then compose a 
true proboscis. In other sucking insects (lepidoptera) the 
jaws alone are considerably prolonged, and unite to form a 
tubular body, in the form of a thread, having the appearance 
of a long tongue, very fine, and rolled up spirally, ( spiri - 
trompe , Lat.) ; the other parts of the mouth are very much 
diminished. Sometimes, as in many Crustacea, the anterior 
feet approach the jaws, assuming their form, exercising a 
part of their functions, and one might then say that the jaws 
are multiplied. It may even happen that the jaws shall be so 
much reduced, that the maxillary feet, otherwise jaw-feet , 
may replace them altogether. But whatever may be the mo- 
difications of these parts, there is always a means of recog- 
nizing them, and of reducing these changes to a general 
type. 
